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7 


SYSTEM  OF  ANATOMY 


FOR  THE  USE  OF 


STUDENTS  OF  MEDICINE . 


BY  CASPAR  WISTAR,  M.  D. 

PROFESSOR  OF  ANATOMY 

IN  THE 

UNIVERSITY  OF  PENNSYLVANIA. 


VOLUME  II. 


PHILADELPHIA: 

PUBLISHED  BY  THOMAS  DOBSON  AND  SON,  AT  THE  STONE  HOUSE, 
No.  41,  SOUTH  SECOND  STREET. 

William  Fry,  Printer. 

1817. 


District  of  Pennsylvania,  to  wit: 

BE  IT  REMEMBERED,  That  on  the  twelfth  day  of  November, 
» ‘jt  L,..  jn  ^jle  fol'ty-second  year  of  the  independence  of  the  United  States 
••••».••**  America,  A.  D 1817',  Thomas  Dobson  and  Son,  of  the  said  dis- 
trict, have  deposited  in  this  office  the  title  of  a book,  the  right,  whereof  they 
claim  as  proprietors,  in  the  words  following,  to  wit: 

“ A System  of  Anatomy  for  the  use  of  Students  of  Medicine.  By  Caspar  Wis- 
“ tar,  M.  D.  Professor  of  Anatomy  in  the  University  of  Pennsylvania. 
“ Volume  II.” 

In  conformity  to  the  act  of  the  congress  of  the  United  States,  intituled,  “An 
act  for  the  encouragement  of  learning,  by  securing  the  copies  of  maps,  charts 
and  books,  to  the  authors  and  proprietors  of  such  copies,  during  the  times 
therein  mentioned.” — And  also  to  the  act,  entitled,  “ An  act  supplementary 
to  an  act,  entitled  “An  act  for  the  encouragement  of  learning,  by  securing  the 
copies  of  maps,  charts,  and  books,  to  the  authors  and  proprietors  of  such  copies 
during  the  times  therein  mentioned,”  and  extending  the  benefits  thereof  ts 
the  arts  of  designing,  engraving,  and  etching  historical  and  other  prints.” 

D.  CALDWELL, 

Clerk  of  the  district  of  Pennsylvania. 


CONTENTS  OF  VOL.  II. 


PART  VI. 

OF  THE  NOSE— THE  MOUTH— AND  THE  THROAT. 

CHAPTER  I. 

Of  the  Nose. 

SECTION  I. 

Page 

UF  the  External  Nose  -----  2 

SECTION  II. 

Of  the  Cavities  of  the  Nose  ....  4 

CHAPTER  II. 

Of  the  Mouth  and  the  Salivary  Glands. 

Of  the  Mouth  - ....  14 

Salivary  Glands  -----  24 

CHAPTER  III. 

Of  the  Throat. 


SECTION  I. 

Of  the  Isthmus  of  the  Fauces  - - - -29 

SECTION  II. 

Of  the  Larynx  - - - - - - 31 

Thyroid  Gland  - - - * - 36 

SECTION  III. 

©f  the  Pharynx  ------  3f 


PART  VII. 

OF  THE  THORAX. 

CHAPTER  I. 

Of  the  general  Cavity  of  the  Thorax. 

SECTION  I.. 

Of  the  Form  of  the  Cavity  of  the  Thorax 


44 


IV 


CONTENTS. 


SECTION  II. 

Of  the  Arrangement  of  the  Pleurae 
Preparation  of  the  Thorax 


Page 

45 

47 


CHAPTER  II. 

Of  the  Heart  and  the  Pericardium,  and  the  Great  Vessels  connected 
with  the  Heart. 


SECTION  I. 

Of  the  Pericardium  .....  49 


SECTION  II. 

Of  the  Heart  - - - - - 50 

SECTION  III. 

Of  the  Aorta,  the  Pulmonary  Artery  and  Vein,  and  the  Venae 
Cavae  at  their  commencement  59 


CHAPTER  III. 

Of  the  Trachea  and  Lungs . 


SECTION  I. 

Of  the  Trachea  - - - - - - 61 

The  Black  Glands  on  the  Bronchiae  - - - 64 

SECTION  II. 

Of  the  Lungs  - - - . - 64 

Thorax  of  the  Foetus  ...  - - 67 

Physiological  Observations,  &c.  - - - - 70 


PART  VIII. 

OP  THE  ABDOMEN. 

CHAPTER  I. 

si  general  view  of  the  Abdomen  and  Pelvis , and  their  Contents ; with 
an  Account  of  the  Peritoneum. 

SECTION  I. 

Construction  of  the  Abdomen  - - - - 81 

Contents  of  the  Abdomen  - - - - - 86 

SECTION  II. 

Of  the  Peritoneum  .....  88 


CONTENTS.  v 

Fag« 

CHAPTER  II. 

Of  the  QLsofihagusythe  Stomach , and  the  Intestines. 
SECTION  I. 

Of  the  (Esophagus  - - - - - 93 

SECTION  II. 

Of  the  Stomach  - - - - - - 95 

Gastric  Liquor  .....  1Q0 

SECTION  III. 

Of  the  Intestines  .... 

Division  of  the  Intestines  - 
The  Small  Intestines  - 

The  Duodenum  ------ 

Jejunum  and  Ileon  .... 

The  Mesentery  - 

Of  the  Great  Intestines  - 
The  Caecum  and  Colon  - 

The  Rectum  - 

The  Omentum  .... 

CHAPTER  III. 

Of  the  Liver,  the  Pancreas,  and  the  SfUeen. 

SECTION  I. 

Of  the  Liver  ......  125 

SECTION  II. 

Of  the  Pancreas  - - - . - 139 


103 

- 108 
109 

- 110 
111 

- 113 
115 

- 116 
120 
124 


SECTION  HI. 

Of  the  Spleen  - - - - - - 141 


CHAPTER  IV. 

Of  the  Urinary  Organs , and  the  Glandule  Renales . 


SECTION  I. 

Of  the  Glandulae  Renales 

a 

e 

150 

SECTION  II. 
Of  the  Kidneys  and  Ureters 

. 

- 

152 

SECTION  III. 
Of  the  Urinary  Bladder  ... 

157 

VI 


CONTENTS. 


CHAPTER  V. 

Of  the  Male  Organs  of  Generation . 

SECTION  I. 

Of  the  Testicles  and  their  Appendages  ...  i gg 
SECTION  II. 

Of  the  Vesiculse  Seminales  and  the  Prostate  Gland  - 176 

SECTION  III. 

Of  the  Penis  - - - - - - 179 

CHAPTER  VI. 

Of  the  Female  Organs  of  Generation* 

SECTION  I. 

Of  the  External  Parts  of  Generation  - - - 192 

SECTION  II. 

Of  the  Vagina  ......  195 

SECTION  III. 

Of  the  Uterus,  the  Ovaries,  and  their  appendages  - 197 

SECTION  IV. 

Of  the  Bladder  and  Urethra  -----  205 

PART  IX. 

OP  THE  BLOODVESSELS. 

CHAPTER  I. 

Of  the  General  Structure  and  Arrangement  of  the  Bloodvessels. 
SECTION  I. 

Of  the  Arteries  - - - - - - 217 

SECTION  II. 

Of  the  Veins  ......  224 

CHAPTER  II. 

A Particular  Account  of  the  Distribution  of  the  Arteries. 


SECTION  I. 

Of  the  Aorta,  or  the  Great  Trunk  of  the  Arterial  System  227 
SECTION  II. 

Of  the  Branches  which  go  off  from  the  Arch  of  the  Aorta  229 
The  Carotid  Arteries  .....  230 

The  Subclavian  Arteries  ....  247 


CONTENTS. 

vii 

Page 

SECTION  III. 

Of  the  Branches  which  go  off  between  the  Arch  and  the  Great 

Bifurcation  of  the  Aorta  - 

- 

- 

262 

Bronchial  Arteries  ... 

- 

- 

ib. 

CEsophageal  Arteries  ... 

- 

- 

ib. 

Inferior  Intercostals  ... 

- 

- 

263 

Phrenic  Arteries  - 

- 

* 

265 

Cceliac  Artery  .... 

- 

- 

ib. 

Superior  Mesenteric  Artery  - 

- 

- 

268 

Inferior  Mesenteric  Artery 

- 

- 

270 

Emulgent  or  Renal  Arteries 

- 

- 

271 

Capsular  and  Adipose  Artei’ies 

- 

- 

ib. 

Spermatic  Arteries  - 

- 

- 

ib. 

Lumbar  Arteries  ... 

- 

- 

273 

Middle  Sacral  Artery  ... 

- 

- 

ib. 

SECTION  IV. 

Of  the  Arteries  which  originate  at  and  below  the  Great  Bifur- 

cation  of  the  Aorta  - 

- 

- 

273 

The  Primitive  Iliac  Arteries 

- 

- 

ib. 

Internal  Iliac  Arteries  ... 

- 

- 

274 

External  Iliac  Arteries  - 

. 

- 

279 

Femoral  Artery  ... 

- 

- 

280 

Arteries  of  the  Leg  - 

- 

- 

283 

CHAPTER  III. 

Of  the  particular  Distribution  of  the  Veins. 

SECTION  I. 

Of  the  Superior,  or  Descending  Vena  Cava, 

and  the 

Veins 

which  communicate  with  it  - 

- 

- 

291 

Vena  Azygos  .... 

- 

- 

292 

Internal  Jugular  Veins  - - - 

- 

- 

295 

External  Jugular  Veins  ... 

- 

- 

297 

Subclavian  Vein  - - - 

. 

- 

298 

SECTION  II. 

Of  the  Inferior  Vena  Cava,  and  the  Veins  connected  with  it 

300 

Hepatic  Veins  .... 

- 

- 

301 

Vena  Portarum  .... 

- 

- 

302 

Emulgent  or  Renal  Veins 

- 

- 

303 

Spermatic  Veins  .... 

- 

- 

ib. 

Lumbar  Veins  .... 

- 

- 

304 

Middle  Sacral  Vein  - - ■ - 

- 

- 

ib. 

Primitive  Iliac  Veins  - 

- 

- 

ib 

CONTENTS. 


viii 

Internal  Iliac  Veins 
External  Iliac 
Femoral  Vein 

Instances  of  Peculiar  Arrangement  of  the  Veins  - 
Of  the  Pulmonary  Artery  and  Veins 

PART  X. 

OF  THE  NERVES. 

Nerves  of  the  Brain  - 
Of  the  Cervical  Nerves  - - 

Nerves  of  the  Diaphragm  - 

Brachial  Plexus  - 
Nerves  of  the  Arm  - 

The  Dorsal  Nerves  .... 

Of  the  Lumbar  Nerves  ... 

The  Sacral  Nerves  .... 

Sciatic  Plexus  .... 

Great  Sciatic  Nerve  .... 

Great  Sympathetic  Nerve  - - 

Nerves  of  the  Heart  .... 

Nerves  of  the  Abdominal  Viscera 

PART  XI. 

OF  THE  ABSORBENT  VESSELS. 

CHAPTER  I. 

Of  the  Absorbents  of  the  Lower  Extremities — the  Abdomen  and  the 

Thorax. 

SECTION  I. 

The  Absorbents  of  the  Lower  Extremities  - - 366 

SECTION  II. 

The  Absorbents  of  the  Abdomen  and  Thorax  - - 371 

CHAPTER  II. 

Of  the  Absorbents  of  the  Head  and  JVeck,  of  the  Ufijier  Extremities , 
and  the  U/i/ier  Part  of  the  Trunk  of  the  Body. 

SECTION  I. 

Of  the  Absorbents  of  the  Head  and  Neck  - - 382 

SECTION  II. 

Of  the  Absorbents  of  the  Arm,  and  the  Upper  Part  of  the  Trunk  383 


- 314 

334 

- 336 
337 

- 338 
342 

- 343 
346 

- 347 
348 

- 351 
353 

- 358 


Page 

304 

305 

306 

307 

308 


SYSTEM  OF  ANATOMY. 


PART  VI. 


OF  THE  nose:  THE  MOUTH:  AND  THE  THROAT. 


CHAPTER  I. 

OF  THE  NOSE. 

THE  prominent  part  of  the  face,  to  which  the  word  nose 
is  exclusively  applied  in  ordinary  language,  is  the  anterior 
covering  of  two  cavities  which  contain  the  organ  of  smell- 
ing- 

These  cavities  are  formed  principally  by  the  upper  max- 
illary and  palate  bones;  and,  therefore,  to  acquire  a com- 
plete idea  of  them,  it  is  necessary  to  study  these  bones,  as 
well  as  the  os  ethmoides,  the  vomer,  and  the  ossa  spongi- 
osa  inferiora,  which  are  likewise  concerned  in  their  forma- 
tion. 

In  addition  to  the  description  of  these  bones,  in  the  ac- 
count of  the  bones  of  the  head,  it  will  be  useful  to  study 
the  description  of  the  cavities  of  the  nose  which  follows 
it.  See  vol.  I,  page  53. 

After  thus  acquiring  a knowledge  of  the  bony  structure, 
the  student  will  be  prepared  far  a description  of  the  softer 
parts. 

Vol.IL 


A 


2 ' 


SECTION  I. 

Of  the  External  Nose. 

THE  superior  part  of  the  nose  is  formed  by  the  ossa 
nasi,  and  the  nasal  processes  of  the  upper  maxillary  bones, 
which  have  been  already  described;  (see  vol.  I,  pages  34 
— 36.)  but  the  inferior  part,  which  is  composed  principally 
of  cartilages,  is  much  more  complex  in  its  structure. 

The  orifice,  formed  by  the  upper  maxillary  and  nasal 
bones,  is  divided  by  a cartilaginous  plate,  which  is  the  an- 
terior and  inferior  part  of  the  septum,  or  partition  between 
the  two  cavities  of  the  nose.  The  anterior  edge  of  this 
plate  projects  beyond  the  orifice  in  the  bones,  and  conti- 
nues in  the  direction  of  the  suture  between  the  ossa  nasi. 
This  edge  forms  an  angle  with  the  lo'wer  edge  of  the  same 
cartilage,  which  continues  from  it,  in  a horizontal  direc- 
tion, until  it  reaches  the  lower  part  of  the  orifice  of  the 
nose,  at  the  junction  of  the  palatine  processes  of  the  up- 
per maxillary  bones;  where  a bony  prominence  is  formed, 
to  which  it  is  firmly  united.  The  upper  p^rt  of  the  ante- 
rior edge  of  this  cartilage,  which  is  in  contact  with  the 
ossa  nasi,  is  flat,  and  is  continued  into  two  lateral  portions 
that  are  extended  from  it,  one  on  each  side,  and  form 
a part  of  the  nose:  these  lateral  portions  are  sometimes 
spoken  of  as  distinct  cartilages;  but  they  are  really  com 
tinuations  of  the  middle  portion  or  septum. 

Below  the  lower  edge  of  these  lateral  portions  are  situ- 
ated the  cartilages  which  form  the  orifices  of  the  nose,  or 
the  nostrils.  Of  these,  there  is  one  of  considerable  size, 
and  several  small  fragments,  on  each  side  of  the  septum. 
Each  of  the  larger  cartilages  forms  a portion  of  an  oval 
ring,  which  is  placed  obliquely  on  the  side  of  the  septum; 
so  that  the  extremity  of  the  oval  points  downward  and 


3 


Of  the  Nose. 

forward,  while  the  middle  part  of  the  oval  is  directed  up- 
wards and  backwards.  The  sides  of  this  cartilage  are  flat, 
and  unequal  in  breadth.  The  narrowest  side  is  internal, 
and  projects  lower  down  than  the  cartilaginous  septum;  so 
that  it  is  applied  to  its  fellow  of  the  other  nostril.  The  ex- 
ternal side  is  broader,  and  continues  backward  and  up- 
ward to  a considerable  distance. 

The  upper  and  posterior  part  of  this  oval  ring  is  defi- 
cient; but  the  remainder  of  the  nostril  consists  of  several 
small  pieces  of  cartilage,  which  are  fixed  in  a ligamentous 
membrane  that  is  connected  by  each  of  its  extremities  to 
the  oval  cartilage,  and  thus  completes  the  orifice. 

The  anterior  parts  of  the  oval  cartilages  form  the  point 
of  the  nose;  and  the  ligamentous  portions,  the  alas  or 
lateral  parts  of  the  nostrils. 

When  the  external  integuments  and  muscles  are  remo- 
ved from  the  lower  portion  of  the  nose,  so  that  the  internal 
membrane  and  these  cartilages  only  remain,  the  inter- 
nal membrane  will  be  found  attached  to  the  whole  bony 
margin  of  each  orifice,  and  to  each  side  of  the  whole  ante- 
rior edge  of  the  middle  cartilage,  which  projects  beyond 
the  bones,  so  that  it  would  close  up  these  openings  of  the 
nose,  if  it  were  not  for  the  orifices  formed  by  the  oval 
cartilages  and  the  ligament  above  described;  but  being 
attached  to  one  edge  only  of  these  cartilages,  the  orifice 
formed  by  them  is  complete. 

The  internal  portions  of  the  oval  cartilages  being  situ- 
ated without  the  septum,  and  applied  to  each  other,  they 
form  the  external  edge  of  the  partition  between  the  nos- 
trils, or  the  columna  nasi;  which  is  very  moveable  upon 
the  edge  of  the  middle  cartilage. 

The  orifices  of  the  nostrils,  thus  constructed,  are  dilated 
by  that  portion  of  the  muscle,  called  Levator  Labii  Supe- 
riors Alaque  Nasi,  which  is  inserted  into  the  alas  nasi. 

They  are  drawn  down  by  the  depressor  labii  superioris. 


4 


Of  the  Cavities  of  the  Nose. 

alasque  nasi.  They  are  pressed  against  the  septum  and  the 
nose  by  the  muscle  called  Compressor  Naris , which  has 
however  an  opposite  effect  when  its  upper  extremity  is 
drawn  upwards  by  those  fibres  of  the  occipito- frontalis, 
which  descend  upon  the  nose,  and  are  in  contact  with  it. 

The  end  of  the  nose  is  also  occasionally  drawn  down, 
by  some  muscular  fibres  which  descend  from  it,  on  the 
septum  of  the  nose,  to  the  orbicularis  oris:  they  are  con- 
sidered as  a portion  of  this  muscle  by  many  anatomists, 
but  were  described  by  Albinus  as  a separate  muscle,  and 
called  Nasalis  Labii  Superioris. 

When  inspiration  takes  place  with  great  force,  the  alae 
nasi  would  be  pressed  against  the  septum  if  they  were  not 
drawn  out  and  dilated  by  some  of  the  muscles  above 
mentioned. 


SECTION  II. 

Of  the  Cavities  of  the  Nose. 

TO  the  description  of  the  osseous  parts  of  the  nasal 
cavities  in  vol.  I,  page  53,  it  ought  now  to  be  added  that 
the  vacuity  in  the  anterior  part  of  the  osseous  septum  is 
filled  up  by  a cartilaginous  plate,  connected  with  the  na- 
sal lamella  of  the  ethmoid  bone  above,  and  with  the  vo- 
mer below.  This  plate  sends  off  those  lateral  portions  al- 
ready described,  which  form  the  cartilaginous  part  of  the 
bridge  of  the  nose. 

It  should  also  be  observed  that  at  the  back  parts  of 
these  cavities  are  two  orifices  called  the  Posterior  Nares, 
which  are  formed  by  the  palate  bones,  the  vomer,  and  the 
body  of  the  sphenoidal  bone,  and  are  somewhat  oval  in 
figure. 


Schneiderian  Membrane. 


5 


The  nasal  cavities,  thus  constructed,  are  lined  by  a pe- 
culiar membrane,  which  is  called  pituitary  from  its  secre- 
tion of  mucus,  or  Schneiderian  after  an  anatomist  who  de- 
scribed it  with  accuracy.* 

This  membrane  is  very  thick  and  strong,  and  abounds 
with  so  many  bloodvessels,  that  in  the  living  subject  it  is 
of  a red  colour.  It  adheres  to  the  bones  and  septum  of  the 
nose  like  the  periosteum,  but  separates  from  them  more 
easily.  The  surface  which  adheres  to  the  bones  has  some 
resemblance  to  periosteum;  while  the  other  surface  is  soft, 
spongy,  and  rather  villous.  Bichat  seems  to  have  consi- 
dered this  membrane  as  formed  of  two  laminae,  viz:  peri- 
osteum, and  the  proper  mucous  membrane;  but  he  adds, 
that  it  is  almost  impossible  to  separate  them. 

It  has  been  supposed  that  many  distinct  glandular  bo- 
dies were  to  be  seen  in  the  structure  of  this  membrane  by 
examining  the  surface  next  to  the  bones;f  but  this  opi- 
nion is  adopted  by  very  few  of  the  anatomists  of  the 
present  day.  The  texture  of  the  membrane  appears  to  be 
uniform;  and  on  its  surface  are  a great  number  of  follicles 
of  various  sizes,  from  which  flows  the  mucus  of  the  nose. 

These  follicles  appear  like  pits,  made  by  pushing  a pin 
obliquely  into  a surface  which  retains  the  form  of  the  im- 
pression. They  can  be  seen  very  distinctly  with  a common 
magnifying  glass  when  the  membrane  is  immersed  in  wa- 
ter, both  on  the  septum  and  on  the  opposite  surface.  They 
are  scattered  over  the  membrane  without  order  or  regu- 
larity, except  that  in  a few  places  they  occur  so  as  to  form 
lines  of  various  lengths,  from  half  an  inch  to  an  inch.  The 
largest  of  them  are  in  the  lower  parts  of  the  cavities. 

It  may  be  presumed  that  the  secretion  of  mucus  is  ef- 

* Conrad  Schneider,  a German  professor,  in  a large  work, <l  De 
Catarrhis,”  published  about  1660. 

t See  Winslow,  section  X.  No.  337. 


6 Olfactory  Nerves. 

fected  here  by  vessels  which  are  mere  continuations  of  ar- 
teries spread  upon  a surface  analogous  to  the  exhalents, 
and  not  convoluted  in  circumscribed  masses,  as  in  the 
case  of  ordinary  glands. 

The  arteries  of  this  membrane  are  derived  from  various 
sources:  the  most  important  of  them  is  the  nasal  branch 
of  the  internal  maxillary,  which  passes  into  the  nose 
through  the  spheno-palatine  foramen,  and  is  therefore 
called  the  Spheno-palatine  Artery.  It  divides  into  several 
twigs,  which  are  spent  upon  the  different  parts  of  the  sur- 
face of  the  nasal  cavities.  Two  of  them  are  generally 
found  on  the  septum  of  the  nose:  one,  which  is  small, 
passes  forwards  near  the  middle;  the  other,  which  is  much 
larger,  is  near  the  lower  part  of  it. 

Two  small  arteries  called  the  anterior  and  posterior 
ethmoidal , which  are  branches  of  the  ophthalmic,  enter  the 
nose  by  foramina  of  the  cribriform  plate  of  the  ethmoidal 
bone.  These  arteries  pass  from  the  orbit  to  the  cavity  of 
the  cranium,  and  then  through  the  cribriform  plate  to  the 
nose.  In  addition  to  these,  there  are  some  small  arteries 
derived  from  the  infra  orbital,  the  alveolar  and  the  pala- 
tine, which  extend  to  the  Schneiderian  membrane;  but  they 
are  not  of  much  importance. 

The  veins  of  the  nose  correspond  with  the  arteries. 
Those  which  accompany  the  ethmoidal  arteries  open  into 
the  ocular  vein  of  the  orbit,  which  terminates  in  the  ca- 
vernous sinuses  of  the  head.  The  other  veins  ultimately 
terminate  in  the  external  jugulars. 

The  nerves  of  the  nose  form  an  important  part  of  the 
structure:  they  are  derived  from  several  sources;  but  the 
most  important  branches  are  those  of  the  olfactory. 

The  olfactory  nerves  form  oblong  bulbs,  which  lie  on 
each  side  of  the  crista  galli,  on  the  depressed  portions  of 
the  cribriform  plate  of  the  ethmoid  bone,  within  the  dura 
mater.  These  bulbs  are  of  a soft  consistence,  and  resem- 


7 


Olfactory  Nerves. 

ble  the  cortical  part  of  the  brain  mixed  with  streaks  of 
medullary  matter.  They  send  off  numerous  filaments, 
which  pass  through  the  foramina  of  the  ethmoid  bone,  and 
receive  a coat  from  the  dura  mater  as  they  pass  through  it. 

These  filaments  are  so  arranged  that  they  form  two 
rows,  one  running  near  to  the  septum,  and  the  other  to 
the  surface  of  the  cellular  part  of  the  ethmoid  bone,  and 
the  os  turbinatum:  and  in  addition  to  these  are  some  in- 
termediate filaments. 

When  the  Schneiderian  membrane  is  peeled  from  the 
bones  to  which  it  is  attached,  these  nervous  filaments  are 
seen  passing  from  the  foramina  of  the  ethmoid  bone  to 
the  attached  surfaces:  one  row  passing  upon  that  which 
covered  the  septum,  and  the  other  to  that  of  the  opposite 
side;  while  the  intermediate  filaments  take  an  anterior  di- 
rection, but  unite  to  the  membrane  as  soon  as  they  come 
in  contact  with  it. 

All  of  these  can  be  traced  downwards  on  the  aforesaid 
surfaces  of  the  membrane  for  a considerable  distance, 
when  they  gradually  sink  into  the  substance  of  the  mem- 
brane, and  most  probably  terminate  on  the  internal  vil- 
lous surface;  but  they  have  not  been  traced  to  their  ulti- 
mate termination.  They  ramify  so  that  the  branches  form 
very  acute  angles  with  each  other.  On  the  septum  the 
different  branches  are  arranged  so  as  to  form  brushes, 
which  lie  in  contact  with  each  other.  On  the  opposite 
sides,  the  different  ramifications  unite  so  as  to  form  a 
plexus. 

Dr.  Soemmering  published  last  year  some  very  ele- 
gant engravings  of  the  nose,  representing  one  of  his  dis- 
sections, which  appears  to  have  been  uncommonly  mi- 
nute and  successful.*  These  represent  the  ramifications 
as  becoming  more  expanded  and  delicate  in  the  progress 


* They  are  intitfed,  leones  organorum  humanorum  olfactus-. 


8 Spheno-palatine  and  other  Nerves  of  the  Nose. 

towards  their  terminations,  and  as  observing  a tortuous' 
course,  with  very  short  meandering  flexures. 

It  is  to  be  observed  that  the  ramifications  of  the  olfac- 
tory nerve,  thus  arranged,  do  not  extend  to  the  bottom  of 
the  cavity.  On  the  external  side,  they  are  not  traced  lower 
than  the  lower  edge  of  the  ethmoid,  or  of  the  superior 
spongy  bone:  and  on  the  septum,  they  do  not  extend  to 
the  bottom,  although  they  are  lower  than  on  the  opposite 
side.  On  the  parts  of  the  membrane  not  occupied  by  the 
branches  of  the  olfactory  nerve,  several  other  nerves  can 
be  traced.  The  nasal  twig  of  the  ophthalmic  branch  of  the 
fifth  pair,  after  passing  from  the  orbit  into  the  cavity  of 
the  cranium,  proceeds  to  the  nasal  cavity  on  each  side  by 
a foramen  of  the  cribriform  plate;  and  after  sending  off 
some  fibrillse,  descends  upon  the  anterior  part  of  the  sep- 
tum to  the  point  of  the  nose.  The  spheno  palatine  nerve, 
which  is  derived  from  the  second  branch  of  the  fifth  pair, 
and  enters  the  nose  by  the  spheno-palatine  foramen,  is 
spread  upon  the  lower  part  of  the  septum  and  of  the  oppo- 
site side  of  the  nose  also,  and  transmits  a branch  through 
a canal  in  the  foramen  incisivum  to  the  mouth.  Several 
small  branches  also  pass  to  the  nose  from  the  palatine  and 
other  nerves;  but  those  already  mentioned  are  the  most 
important. 

A question  has  been  proposed,  whether  the  olfactory 
nerve  is  exclusively  concerned  in  the  function  of  smelling, 
or  whether  the  other  nerves  above  mentioned  are  also  con- 
cerned in  it.  It  seems  probable  that  this  function  is  ex- 
clusively performed  by  the  olfactory  nerve,  and  that  the 
other  nerves  are  like  the  ophthalmic  branch  of  the  fifth 
pair,  with  respect  to  the  optic  nerve.  In  proof  of  this,  it  is 
asserted  that  the  sense  of  smelling  has  entirely  ceased  in 
some  cases,  where  the  sensibility  to  mechanical  irritation 
of  every  kind  has  remained  unchanged.  If  the  olfactory 
nerve  alone  is  concerned  in  the  function  of  smelling,  it 


Extent  of  the  Schneiderian  Membrane.  9 

follows,  that  this  function  must  be  confined  to  the  upper 
parts  of  the  nasal  cavities;  but  it  ought  to  be  remembered, 
that  the  structure  of  the  Schneiderian  membrane,  in  the 
lower  parts  of  these  cavities,  appears  exactly  like  that 
which  is  above. 

The  surface  of  the  nasal  cavities  and  their  septum, 
when  covered  with  the  Schneiderian  membrane,  corres- 
ponds with  the  osseous  surface  formerly  described.  The 
membrane  covers  the  bones  and  cartilage  of  the  septum, 
so  as  to  make  one  uniform  regular  surface.  From  the 
upper  part  of  the  septum,  it  is  continued  to  the  under 
side  of  the  cribriform  plate  of  the  ethmoid,  and  lines  it; 
the  filaments  of  the  olfactory  nerve  passing  through  the 
foramina  of  that  bone  into  the  fibrous  surface  of  the  mem- 
brane. It  is  continued  from  the  septum,  and  from  the 
cribriform  plate,  to  the  internal  surface  of  the  external 
nose,  and  lines  it.  It  is  also  continued  backwards  to  the 
anterior  surface  of  the  body  of  the  sphenoidal  bone;  and, 
passing  through  the  foramina  or  openings  of  the  sphe- 
noidal cells,  it  lines  these  cavities  completely;  but  in 
these,  as  well  as  the  other  cavities,  its  structure  appears 
somewhat  changed:  it  becomes  thinner  and  less  vascular. 

At  the  above  mentioned  foramina,  in  some  subjects,  it 
forms  a plait  or  fold,  which  diminishes  the  aperture  con- 
siderably. 

From  the  upper  surface  of  the  nasal  cavities,  the  mem- 
brane is  continued  downwards  over  the  surface  opposite 
to  the  septum.  On  the  upper  flat  surfaces  of  the  cellular 
portions  of  the  ethmoid,  it  forms  a smooth  uniform  sur- 
face. After  passing  over  the  first  turbinated  bone,  or  that 
called  after  Morgagni,  it  is  reflected  into  the  groove,  or 
upper  meatus,  immediately  within  and  under  it:  the  fold 
formed  by  the  membrane,  as  it  is  reflected  into  the  mea- 
tus, is  rather  larger  than  the  bone;  and  the  edge  of  the 
fold  therefore  extends  lower  down  than  the  edge  of  the 

Vol.  II.  B 


10  Distribution  of  the  Schneiderian  Membrane . 

bone,  and  partly  covers  the  meatus  like  a flap,  consisting 
only  of  the  doubled  membrane.  This  fold  generally  con- 
tinues backwards  as  far  as  the  spheno-maxillary  foramen, 
which  it  closes;  the  periosteum,  exterior  to  the  foramen, 
passing  through  it,  and  blending  itself  with  the  fibrous 
surface  of  the  Schneiderian  membrane  within.  Here  the 
spheno-palatine  nerves  and  arteries  join  the  membrane. 
Below  this  meatus,  it  extends  over  the  middle  (formerly 
called  the  upper)  turbinated  bone,  and  is  reflected  or  fold- 
ed inwards  on  the  under  side  of  this  bone,  and  continued 
into  the  middle  meatus  below  it.  In  the  middle  meatus, 
which  is  partly  covered  by  the  last  mentioned  turbinated 
bone,  there  are  two  foramina:  one  communicating  with 
the  maxillary  sinus;  and  the  other  with  the  anterior  cells 
of  the  ethmoid  and  the  frontal  sinuses.  The  aperture  into 
the  maxillary  sinuses  is  much  less  in  the  recent  head,  in 
which  the  Schneiderian  membrane  lines  the  nose,  than  it 
is  in  the  bare  bones.  A portion  of  the  aperture  in  the 
bones  is  closed  by  the  Schneiderian  membrane,  which  is 
extended  over  it:  the  remainder  of  the  aperture  is  unclos- 
ed; and  through  this  foramen,  the  membrane  is  reflected 
so  as  to  line  the  whole  cavity.  As  a portion  of  the  fora- 
men is  covered  by  the  membrane,  and  this  portion  as  well 
as  the  other  parts  of  the  cavity  is  lined  by  the  membrane, 
it  is  obvious  that  at  the  place  where  the  membrane  is  ex- 
tended over  the  foramen  in  the  bone,  it  must  be  doubled; 
or,  in  other  words,  a part  of  the  aperture  of  the  maxillary 
sinus  is  closed  by  a fold  of  the  Schneiderian  membrane. 

This  aperture  varies  in  size  in  different  subjects,  and  is 
often  equal  in  diameter  to  a common  quill.  It  is  situated 
in  the  middle  meatus,  and  is  covered  by  the  middle  turbi- 
nated bone:  immediately  above  it,  is  a prominence  of  the 
cellular  structure  of  the  ethmoid  bone,  which  has  a curved 
or  semicircular  figure.  Near  this  prominence,  in  the  same 


Eustachian  Tube. -Observations  respecting  the  Nose.  11 

meatus,  a groove  terminates,  which  leads  from  the  anterior 
ethmoid  cells  and  the  frontal  sinuses. 

From  the  middle  meatus,  the  membrane  proceeds  over 
the  inferior  turbinated  bone,  and  is  reflected  round  and 
under  it  into  the  lower  meatus.  It  appears  rather  larger 
than  the  bone  which  it  covers;  and  therefore  the  lower 
edge  of  the  bone  does  not  extend  so  low  as  the  lower  edge 
of  the  membrane,  which  of  course  is  like  a fold  or  plait. 
The  membrane  then  continues  and  lines  the  lower  meatus: 
here  it  appears  less  full  than  it  is  in  the  turbinated  bone. 
In  this  meatus,  near  to  its  anterior  end,  is  the  lower  orifice 
of  the  lachrymal  duct:  this  is  simply  lined  by  the  Schnei- 
derian membrane,  which  is  continued  into  it,  and  forms 
no  plaits  or  folds  that  affect  the  orifice. 

Orifice  of  the  Eustachian  Tube. 

Immediately  behind  each  of  the  nasal  cavities,  on  the 
external  side,  is  the  orifice  of  the  Eustachian  Tube.  It  has 
an  oval  form,  and  is  large  enough  to  admit  a very  large 
quill.  Its  position  is  oblique;  the  upper  extremity  being 
anterior  to  the  other  parts  of  the  aperture,  and  on  a line 
with  the  middle  meatus,  while  the  center  is  behind  the 
inferior  turbinated  bone.  The  lower  part  of  the  oval  is 
deficient.  This  tube  is  formed  posteriorly  by  a cartilagi- 
nous plate.  It  is  lined  by  the  membrane  continued  from 
the  nose. 

The  cavities  of  the  nose  answer  a twofold  purpose  in  the  ani- 
mal economy:  they  afford  a surface  for  the  expansion 
of  the  olfactory  nerves;  and  a passage  for  the  external 
air  to  the  windpipe,  in  respiration. 

The  function  of  smelling  appears  to  be  dependent,  to  a 
certain  degree,  upon  respiration.  It  has  been  asserted 
that  unless  the  air  passes  in  a stream  through  the  nose, 
as  in  respiration,  the  perception  of  odour  does  not  take 
place;  that  in  persons  who  breathe  through  wounds  and 


12 


Use  of  the  Sinuses  of  the  JVose. 

apertures  in  the  windpipe,  the  function  of  smelling  is 
not  performed.  It  is  rather  in  confirmation  of  this  pro- 
position, that  most  persons,  wfien  they  wish  to  have  an 
accurate  perception  of  any  odour,  draw  in  air  rapidly 
through  the  nose. 

Although  the  ultimate  termination  of  the  olfactory  nerve 
cannot  be  demonstrated  like  those  of  the  optic  and  au- 
ditory nerves,  it  is  probable,  from  the  appearance  of  the 
fibres,  while  they  are  distinguishable,  that  they  are  fi- 
nally arranged  with  great  delicacy.  It  is  certain  that 
the  impressions  from  whence  we  derive  the  perceptions 
of  many  odours  must  be  very  slight;  as  some  odorous 
bodies  will  impregnate  the  air  of  a large  chamber,  for  a 
great  length  of  time,  without  losing  any  sensible  weight. 

With  respect  to  delicacy  of  structure  and  sensibility,  it  is 
probable  that  the  nose  holds  a middle  rank  between  the 
eye  or  ear,  and  the  tongue:  and  on  this  account  the 
mucus  is  necessary  as  a covering  and  defence  of  its 
surface. 

It  has  been  ascertained,  by  the  investigations  of  chemists, 
that  this  mucus  contains  the  same  ingredients  as  the 
tears  already  described,  viz:  animal  mucus  and  water; 
with  muriate  of  soda,  and  soda  uncombined;  phosphate 
of  lime,  and  phosphate  of  soda. 

The  animal  mucus,  which  is  a most  important  ingredient 
in  the  composition,  resembles  the  mucilage  formed  by 
some  of  the  vegetable  gums  in  several  particulars;  and 
differs  from  them  in  others. 

The  mucus  of  the  nose,  if  it  remain  there  long  after  it  is 
secreted,  becomes  much  more  viscid  in  consistence,  and 
changes  from  a whitish  colour  to  one  which  partakes 
more  or  less  of  the  yellow.  It  is  probable  that  an  inci- 
pient putrefaction  may  occasion  these  changes  in  it. 

The  use  of  the  frontal,  maxillary  and  other  sinuses,  com- 
municating with  the  nose,  has  been  the  subject  of  some 
inquiry.  As  there  can  be  no  stream  of  air  through  them, 
and  as  the  membrane  lining  them  is  neither  so  thick, 
villous  nor  flexible  as  that  lining  the  nose,  it  may  be  con- 
cluded, a priori,  that  they  are  not  concerned  in  the  func- 


13 


Use  of  the  Sinuses  of  the  Nose. 

tion  of  smelling.  This  opinion  is  strengthened  by  th« 
fact,  that  very  young  children,  in  whom  these  sinuses 
scarcely  exist,  enjoy  the  sense  of  smelling  in  perfection. 
The  following  fact  is  also  in  support  of  it.  The  celebrated 
Dessault  attended  a patient,  in  whom  one  of  the  frontal 
sinuses  was  laid  open  by  the  destruction  of  the  bone 
which  covered  it  anteriorly.  This  patient  was  able  to 
breathe  a short  time  through  the  sinus  when  the  mouth 
and  nose  were  closed:  At  the  request  of  Dessault  he 
breathed  in  this  manner  when  a cup  of  some  aromatic 
liquor  was  held  near  the  opening  of  the  sinus:  and  had 
not  the  least  perception  of  odour.  This  experiment  was 
repeated  several  times. 

Many  physiologists  believe  that  these  sinuses  have  an  ef- 
fect in  modulating  the  voice. 


14 


CHAPTER  II. 

OF  THE  MOUTH. 

I HE  general  cavity  of  the  mouth  is  formed  anteriorly 
and  laterally  by  the  connexion  of  the  lips  and  checks  to 
the  upper  and  lower  jaws;  so  that  the  teeth  and  the  alveo- 
li of  both  jaws  may  be  considered  as  within  the  cavity. 
Above,  it  is  bounded  principally  by  the  palatine  process- 
es of  the  upper  maxillary  and  palate  bones,  and  the  soft 
palate,  which  continues  backward  from  them  in  the  same 
direction.  Below,  the  cavity  is  completed  by  several  mus- 
cles, which  proceed  from  almost  the  whole  internal  cir- 
cumference of  the  lower  jaw,  and,  by  their  connexions 
with  each  other,  with  the  tongue  and  the  os  hyoides,  form 
a floor  or  bottom  to  it.  The  tongue  is  particularly  connect- 
ed to  this  surface,  and  may  be  considered  as  resting  upon 
and  supported  by  it. 

To  acquire  an  idea  of  the  parietes  of  this  cavity,  after 
studying  the  upper  and  lower  maxillary  bones,  the  orbi- 
cularis oris  and  the  muscles  connected  with  it,  especially 
the  buccinator,  ought  to  be  examined;  and  also  the  digas- 
tricus,  the  mylo-hyoideus,  genio-hyoideus,  and  genio- 
hyoglossus.  By  this  it  will  appear  that  the  lips  and  cheeks, 
and  the  basis  or  floor  of  the  mouth,  are  formed  in  a great 
measure  by  muscles.  Upon  the  internal  surface  of  these 
muscles,  a portion  of  cellular  and  adipose  substance  is  ar- 
ranged, as  well  as  glandular  bodies  of  different  sizes;  and 
to  these  is  attached  the  membrane  which  lines  the  inside 
of  the  mouth. 

This  membrane  passes  from  the  skin  of  the  face  to  the 
lips,  and  the  inside  of  the  mouth;  and,  although  it  is  really 
a continuation  of  the  skin,  there  is  so  great  a change  of 

A, 


15 


Internal  Surface  of  the  Mouth . 

structure,  that  it  ought  to  be  considered  as  a different 
membrane.  At  the  orifice  of  the  lips  it  is  extremely  thin, 
and  so  vascular  that  it  produces  the  fine  florid  colour  which 
appears  there  in  health.  It  is  covered  by  a cuticle,  called 
by  some  anatomists,  Epithelium , which  has  a proportion- 
ate degree  of  delicacy,  and  can  be  separated  like  the  cu- 
ticle in  other  parts.  When  this  cuticle  is  separated,  the 
lips  and . the  membrane  of  the  mouth,  appear  to  be  co- 
vered with  very  fine  villi,  which  are  particularly  apparent 
in  some  preparations  of  the  lips  after  injection  and  ma- 
ceration.* 

Under  this  membrane  are  many  small  glandular  bodies 
of  a roundish  form,  whose  excretory  ducts  pass  through  it 
to  the  inner  surface  of  the  mouth,'  for  the  purpose  of  lubri- 
fying  it  with  their  secretion,  which  is  mingled  with  the 
saliva. 

The  membrane,  which  lines  the  inside  of  the  lips  and 
cheeks,  is  somewhat  different  from  that  which  forms  the 
surface  of  the  orifice  of  the  mouth:  it  is  not  so  florid;  the 
bloodvessels  in  its  texture  are  larger  and  not  so  numerous. 
This  change,  however,  takes  place  very  gradually,  in  the 
progress  of  the  membrane,  from  the  orifice  of  the  lips  to 
the  back  part  of  the  cheeks.  Glandular  bodies,  like  those 
of  the  lips,  are  situated  immediately  exterior  to  this  mem- 
brane of  the  cheeks,  between  it  and  the  muscles:  their 
ducts  open  on  its  surface.  These  glands  are  called  Buc - 
cales. 

This  lining  membrane  is  continued  from  the  internal 
surface  of  the  lips  and  cheeks  to  the  alveolar  portions  of 
the  upper  and  lower  jaws,  which  are  in  the  cavity  of  the 
mouth,  and  covers  them,  adhering  firmly  to  the  perios- 
teum. 

The  teeth  appear  to  have  passed  through  apertures  in 

* Ruysch  had  a fine  preparation  of  this  structure.  See  Thesau- 
rus VII.  Tab.  III.  Fig.  5, 


16  Gums. — Surface  of  the  Hard  Palate. 

this  membrane,  and  are  surrounded  by  it  closely  at  their 
respective  necks. 

The  portion  of  membrane,  which  thus  invests  the  jaws, 
constitutes  the  gums;  which  have  now  acquired  a texture 
very  different  from  that  of  the  membrane,  from  which 
they  were  continued.  They  are  extremely  firm  and  dense, 
and  very  vascular.  It  is  probable  that  their  ultimate  struc- 
ture is  not  perfectly  understood. 

In  the  disease  called  scurvy , they  tumify  and  lose  the 
firmness  of  their  texture:  they  acquire  a livid  colour,  and 
are  much  disposed  to  hemorrhage. 

From  the  alveoli  of  the  upper  jaw,  the  lining  membrane 
is  continued  upon  the  palatine  processes  of  the  upper  max- 
illary and  palate  bones,  or  the  roof  of  the  mouth. 

This  membrane  of  the  palate  is  not  quite  so  firm  as 
that  of  the  gums,  and  is  also  less  florid:  it  adheres  firmly 
to  the  periosteum,  and  thus  is  closely  fixed  to  the  bones. 
There  is  generally  a ridge  on  its  surface,  immediately  un- 
der the  suture  between  the  two  upper  maxillary  bones; 
-and  some  transverse  ridges  are  also  to  be  seen  upon  it. 
On  the  internal  surface  of  this  membrane  are  small  glan- 
dular bodies,  whose  ducts  open  on  the  surface  of  the  pa- 
late. 

It  is  asserted,  that  this  membrane  has  a limited  degree 
of  that  sensibility  which  is  essential  to  the  function  of  tast- 
ing; and,  that  if  certain  sapid  substances  are  carefully 
applied  to  it,  their  respective  tastes  will  be  perceived,  al- 
though they  have  not  been  in  contact  with  the  tongue. 

The  membrane  is  continued  from  the  bones  above 
mentioned  to  the  soft  palate,  or  velum  pendulum  palati, 
which  is  situated  immediately  behind  them.  This  soft  pa- 
late may  be  considered  as  a continuation  of  the  partition 
between  the  nose  and  mouth:  it  is  attached  to  the  posterior 
edge  of  the  palatine  processes  of  the  ossa  palati,  and  to 
the  pterygoid  processes  of  the  sphenoidal  bone*  Its  in- 


17 


Soft  Palate.-— Uvula. 

terior  structure  is  muscular.  The  upper  surface  is  cover- 
ed by  the  membrane  of  the  nose,  the  lower  surface  by 
the  membrane  which  lines  the  mouth. 

The  muscles,  which  contribute  to  the  composition  of 
this  structure,  are  the  circumflexus  and  the  levatores  palati 
above,  and  the  constrictores  isthmi  faucium  and  palato- 
pharyngei  below.  (See  Vol.  I.  page  178 — 179.)  Thus 
composed,  the  soft  palate  constitutes  the  back  part  of  the 
partition  between  the  nose  and  mouth.  When  viewed 
from  before,  with  the  mcuth  open,  it  presents  towards 
the  tongue  an  arched  surface,  which  continues  downwards 
on  each  side  until  it  comes  nearly  in  contact  with  the 
edges  of  that  organ.  On  each  of  the  lateral  parts  of  this 
arch,  are  two  pillars,  or  rather  prominent  ridges,  which 
project  into  the  mouth.  These  ridges  are  at  some  distance 
from  each  other  below,  and  approach  much  nearer  above, 
so  that  they  include  a triangular  space.  They  are  called 
the  lateral  half  arches  of  the  palate.  Each  of  them  is  form- 
ed by  a plait  or  fold  of  the  skin,  and  contains  one  of  the 
two  last  mentioned  muscles:  the  anterior,  the  constric- 
tor isthmi  faucium;  the  posterior,  the  palato-pharyngeus. 
These  muscles,  of  course,  draw  the  palate  down  toward 
the  tongue  when  they  contract. 

From  the  center  of  the  arch,  near  its  posterior  edge,  is 
suspended  the  uvula,  a conical  body,  which  varies  in 
length  from  less  than  half  an  inch  to  rather  more  than  one 
inch.  It  is  connected  by  its  basis  to  the  palate;  but  its 
apex  is  loose  and  pendulous.  This  body  is  covered  by  the 
lining  membrane  of  the  mouth.  It  contains  many  small 
glands,  and  a muscle  also,  the  azygos  uvulas,  which  ari- 
ses from  the  posterior  edge  of  the  ossa  palati,  at  the  su- 
ture which  connects  them  to  each  other,  and,  passing 
posteriorly  upon  the  soft  palate,  extends  from  the  basis 
to  the  apex  of  the  uvula,  into  which  it  is  inserted.  By  the 
the  action  of  this  muscle,  the  length  of  the  uvula  can  be 
Vol.IL  C 


18 


The  Tongue. 

very  much  diminished;  and  when  its  contraction  ceases, 
that  body  is  elongated. 

The  pendulous  part  of  the  uvula  can  also  be  moved,  in 
certain  cases,  to  either  side. 

It  is  commonly  supposed,  that  the  principal  use  of  this 
little  organ  is  to  modulate  the  voice;  but  there  are  good 
reasons  for  believing,  that  it  has  another  object.  It  was 
remarked  by  Fallopius,  (and  the  observation  has  been  con- 
firmed by  many  surgeons  since  his  time)  that  the  uvula 
may  be  removed  completely  without  occasioning  any  alter- 
ation of  the  voice,  or  any  difficulty  in  deglutition,  if  the 
soft  palate  be  left  entire. 

The  soft  palate  is  so  flexible,  that  it  yields  to  the  actions 
of  the  levatores  palati,  which  draw  it  up  so  as  to  close  the 
posterior  nares  completely. 

It  also  yields  to  thecircumflexi  ortensores,  which  stretch 
it  so  as  to  do  away  its  arched  appearance. 

It  is  therefore  very  properly  called  the  Palatum  Molle. 
It  is  also  frequently  called  the  Velum  Pendulum  palati , 
from  the  position  which  it  assumes. 

The  Tongue , 

Which  is  a very  important  part  of  this  structure,  is  re- 
tained in  its  position  and  connected  with  the  parts  adjoin- 
ing it,  by  the  following  arrangements. 

The  os  hyoides,  which,  as  its  name  imports,  resembles 
the  Greek  letter  v,  or  half  an  oval,  is  situated  rather  below 
the  angles  of  the  lower  jaw,  in  the  middle  of  the  upper 
part  of  the  neck.  It  is  retained  in  its  position  by  the  ster- 
no-hyoidei  muscles,  which  connect  it  to  the  upper  part 
of  the  sternum;  by  the  coraco-hyoidei,  which  pass  to  it 
obliquely  from  the  scapula;  by  the  thyro-hyoidei,  which 
pass  to  it  directly  upward  from  the  thyroid  cartilage:  all 
of  which  connect  it  to  parts  below.  To  these  should  be 
added  the  stylo-hyoidei,  which  pass  to  it  obliquely  from 


19 


Structure  of  the  Tongue. 

behind  and  rather  from  above;  the  mylo-hyoidei,  which 
come  rather  anteriorly  from  the  lateral  parts  of  the  lower 
jaw;  and  the  genio-hyoidei,  which  arise  from  a situation 
directly  anterior  and  superior,  the  chin.  When  these 
muscles  are  at  rest,  the  situation  of  the  os  hyoides  is,  as 
above  described,  below  the  angles  of  the  lower  jaw:  when 
those,  in  one  particular  direction,  act  while  the  others  are 
passive,  the  bone  may  be  moved  upwards  or  downwards, 
backwards  or  forwards,  or  to  either  side.  This  bone  may 
be  considered  as  the  basis  of  the  tongue;  for  the  posterior 
extremity  of  that  organ  is  attached  to  it;  and  of  course 
the  movements  of  the  bone  must  have  an  immediate  ef- 
fect upon  those  of  the  tongue. 

The  tongue  is  a fiat  body  of  an  oval  figure,  but  subject 
to  considerable  changes  of  form. 

The  posterior  extremity,  connected  to  the  os  hyoides, 
is  commonly  called  its  basis;  the  anterior  extremity,  which 
when  the  tongue  is  quiescent,  is  rather  more  acute,  is 
called  its  apex. 

The  lower  surface  of  the  tongue  is  connected  with  a 
number  of  muscles,  which  are  continued  into  its  sub- 
stance. This  connexion  is  such,  that  the  edges  of  the 
tongue  are  perfectly  free  and  unconnected;  and  so  is  the 
anterior  extremity  for  a considerable  distance  from  the 
apex  towards  the  base. 

The  substance  of  the  tongue  consists  principally  of 
muscular  fibres  intermixed  with  a delicate  adipose  sub- 
stance. It  is  connected  to  the  os  hyoides  by  the  hyoglos- 
sus  muscle  and  also  by  some  other  muscular  fibres,  as 
well  as  by  a dense  membranous  substance,  which  appears 
to  perform  the  part  of  a ligament.  This  connexion  is  also 
strengthened  by  the  continuance  of  the  integuments  from 
the  tongue  to  the  epiglottis  cartilage,  to  be  hereafter  de- 
scribed; for  that  cartilage  is  attached  by  ligaments  to  the 
os  hyoides. 


20 


Structure  of  the  Tongue . 

The  tongue  is  thin  at  its  commencement  at  the  os  hy; 
oi.des;  but  it  soon  increases  in  thickness.  The  muscular 
fibres  in  its  composition  have  been  considered  as  intrinsic, 
or  belonging  wholly  to  its  internal  structure;  and  extrinsic, 
r existing  in  part  outside  of  this  structure.  The  linguales 
: scies  are  intrinsic:  (Vol.  I,  page  175.)  they  are  situa- 

d near  the  under  surface  of  the  tongue,  one  on  each  side, 
separated  from  each  other  by  the  genio-glossi  muscle,  and 
extending  from  the  basis  of  the  tongue  to  its  apex.  These 
muscles  can  be  easily  traced  as  above  described;  but 
there  are  also  many  fibres  in  the  structure  of  the  tongue, 
which  seem  to  pass  in  every  direction,  and  of  course  are 
different  from  those  of  the  linguales  muscles.  To  these 
two  sets  of  fibres  are  owing  many  of  the  immensely  varied 
motions  of  the  different  parts  of  the  tongue. 

In  addition  to  these,  are  the  extrinsic  muscles,  which 
originate  from  the  neighbouring  parts,  and  are  inserted 
and  continued  into  the  substance  of  the  tongue. 

Among  the  most  important  of  these  muscles,  are  those 
which  proceed  from  the  chin,  or  the  genio-hyoglossi. 
They  are  in  contact  with  each  other;  their  fibres  radiate 
from  a central  point  on  the  inside  of  the  chin,  and  are 
inserted  into  the  middle  of  the  lower  surface  of  the  tongue: 
the  insertion  commencing  at  a short  distance  from  its 
apex,  and  continuing  to  its  base. 

As  the  genio-hyo-glossi  muscles  have  a considerable 
degree  of  thickness,  they  add  much  to  the  bulk  of  the 
tongue  in  the  middle  of  the  posterior  parts  of  it. 

The  hyo-glossi  and  the  stylo-glossi,  being  continued 
into  the  posterior  and  lateral  parts,  contribute  also  to  the 
bulk  of  these  parts. 

The  tongue,  thus  composed  and  connected,  lies,  when 
at  rest,  on  the  mylo-hyoidei  muscles;  and  the  space  be- 
tween it  and  these  muscles  is  divided  into  two  lateral 
parts  by  the  above  described  genio-glossi.  In  the  space 


21 


Papilla  of  the  Tongue. 

above  mentioned,  is  a small  salivary  gland,  of  an  irregular 
oval  form;  the  greatest  diameter  of  which  extends  from 
before  backwards;  and  its  edges  present  outwards  and  in- 
wards. It  has  several  excretory  ducts,  the  orifices  of  which 
form  a line  on  each  side  of  the  tongue.  This  gland  is 
very  prominent  under  the  tongue;  and  when  the  tongue 
is  raised  it  is  particularly  conspicuous:  it  is  called  the 
Sublingual. 

The  lining  membrane  of  the  mouth  continues  from 
the  inside  of  the  alveoli  of  the  lower  jaw,  which  it  covers, 
over  the  sublingual  glands  to  the  lower  surface  of  the 
tongue.  In  this  situation  it  is  remarkably  thin;  but,  as  it 
proceeds  to  the  upper  surface  of  the  tongue,  its  texture 
changes  considerably;  and  on  this  surface  it  constitutes 
the  organ  of  taste. 

The  upper  surface  of  the  tongue,  although  it  is  con- 
tinued from  the  thin  membrane  above  described,  is  form- 
ed by  a rough  integument  which  consists,  like  the  skin, 
of  three  laminas.  The  cuticle  is  very  thin;  and  under 
it,  the  rete  mucosum*  is  thicker  and  softer  than  in  other 
places. 

The  true  skin  here  abounds  with  eminences  of  various 
sizes  and  forms,  all  of  which  are  denominated  Papilla. 
The  largest  of  these  are  situated  on  the  posterior  part  of 
the  tongue,  and  are  so  arranged  that  they  form  an  angle 
rather  acute,  with  its  point  backwards.  They  are  com- 
monly nine  in  number:  they  resemble  an  inverted  cone; 
or,  are  larger  at  their  head  than  their  basis.  They  are 
situated  in  pits  or  depressions,  to  the  bottoms  of  which 
they  are  connected.  In  many  of  them  there  are  follicles, 
or  perforations,  which  have  occasioned  them  to  be  re- 

* M.  Bichat  appears  to  have  had  doubts  whether  the  real  rete  mu- 
cosum  existed  here.  He  says  that  he  could  only  perceive  a decus- 
sation of  vessels  in  the  intervals  of  the  papillae,  which,  as  he  supposes, 
occasioned  the  florid  colour  of  the  tongue. 


/ 


22  Pap'tllee  of  the  Tongue. 

garde  cl  as  glands.  They  are  called  Papilla  Maxima , or 
Capital  a. 

The  papillae,  next  in  size,  are  denominated  fungiform 
by  some  anatomists,  and  Media  or  Semilenticulares  by 
others.  They  are  nearly  cylindrical  in  form,  with  their 
upper  extremities  regularly  rounded.  They  are  scattered 
over  the  upper  surface  of  the  tongue,  in  almost  every  part 
of  it,  at  irregular  distances  from  each  other. 

The  third  class  are  called  conoidal  or  villous.  They  are 
very  numerous,  and  occupy  the  greatest  part  of  the  sur- 
face of  the  tongue.  Although  they  are  called  conoidal , 
there  is  a great  difference  in  their  form;  many  of  them 
being  irregularly  angular  and  serrated,  as  well  as  conical. 

Soemmering  and  other  German  anatomists  consider 
the  smallest  papillts  as  a fourth  class,  which  they  call  the 
fliform:  these  lie  between  the  others. 

It  is  probable  that  these  papillae  are  essential  parts  of 
the  organ  of  taste;  and  their  structure  is  of  course  an  in- 
teresting object  of  inquiry. 

The  nerves  of  the  tongue  have  been  traced  to  the  papil- 
lae, and  have  been  compared  by  some  anatomists  to  the 
stalk  of  the  apple,  while  the  papillae  resembled  the  fruit; 
but  their  ultimate  termination  does  not  appear  to  have 
been  ascertained.* 

Soemmering  has  lately  published  some  elegant  engraved 
copies  of  drawings  of  these  papillae,  when  they  were  mag- 
nified twenty-five  times;  from  which  it  appears  that  a 
very  large  number  of  vessels,  particularly  of  arteries,  ex- 

* In  the  explanation  of  the  plates,  referred  to  in  the  following  sen- 
tence, Soemmering  observes,  that  when  the  fibrillae  of  the  lingual 
nerve  of  the  fifth  pair  are  traced  to  the  papillae  of  the  second  class, 
they  swell  out  into  a conical  form;  and  these  nervous  cones  are  in 
such  close  contact  with  each  other,  that  the  point  of  the  finest  nee- 
dle could  not  be  insinuated  into  the  papillae  without  touching  a 


nerve. 


23 


Bloodvessels  of  the  Tongue ; 

ist  in  them.  These  vessels  are  arranged  in  a serpentine 
direction,  and  are  prominent  on  the  surface;  but  they  ap- 
pear doubled,  and  the  most  prominent  part  is  the  doubled 
end.  This  arrangement  of  vessels  is  perceptible  on  the 
sides  of  the  tongue,  as  well  as  on  the  papilla. 

Behind  the  large  papilla  is  a foramen,  first  described 
by  Morgagni,  and  called  by  him  Foramen  Cacum.  It  is 
the  orifice  of  a cavity  which  is  not  deep;  the  excretory 
ducts  of  several  mucous  glands  open  into  it. 

On  the  upper  surface  of  the  tongue,  a groove  is  often 
to  be  seen,  which  is  called  the  linea  mediana , and  divides 
it  into  two  equal  lateral  parts.  Below,  the  lining  mem- 
brane of  the  mouth,  as  it  is  continued  from  the  lower  jaw 
to  the  tongue,  forms  a plait,  which  acts  as  a ligament, 
and  is  called  the  franum  lingua.  It  is  attached  to  the  mid- 
dle of  the  tongue,  at  some  distance  behind  the  apex. 

The  tongue  is  well  supplied  with  bloodvessels,  which 
are  derived  from  the  lingual  branch  of  the  external  carotid 
on  each  side.  This  artery  passes  from  the  external  carotid, 
upwards,  inwards,  and  forwards,  to  the  body  of  the  tongue. 
In  this  course  it  sends  off  several  small  arteries  to  the  con- 
tiguous parts,  and  one,  which  is  spent  about  the  epiglottis 
and  the  adjoining  parts,  called  the  Dorsalis  Lingua.  About 
the  anterior  edge  of  the  hyo-glossus  muscle,  it  divides  into 
two  large  branches:  one  of  which,  called  the  Sublingual , 
passes  under  the  tongue  between  the  genio-glossus  and 
the  sublingual  gland,  and  extends  near  to  the  symphysis 
of  the  upper  jaw;  sending  branches  to  the  sublingual 
gland,  to  the  muscles  under  the  tongue,  to  the  skin,  and 
the  lower  lip.  The  other  is  in  the  substance  of  the  tongue, 
on  the  under  side  near  the  surface,  and  extends  to  the  apex. 

The  veins  of  this  organ  are  not  so  regular  as  the  arte- 
ries: they  communicate  with  the  external  jugular;  and 
some  of  them  are  always  very  conspicuous  under  the 
tongue:  these  are  called  ranular.  ' 


24 


The  Salivary  Glands. 

It  is  to  be  observed,  that  the  vessels  on  each  side  have 
but  little  connexion  with  each  other;  for  those  of  one  side 
may  be  injected  while  the  others  continue  empty. 

The  tongue  is  also  well  supplied  with  nerves,  and  de- 
rives them  from  three  different  sources  on  each  side,  viz.: 
from  the  fifth,  the  eighth,  and  ninth  pairs  of  the  head. 

The  lingual  portion  of  the  third  branch  of  the  fifth  pair, 
passing  under  the  tongue,  enters  its  substance  about  the 
middle,  and  forms  many  minute  branches,  which  pass  to 
the  papillae  of  the  fore  part  of  the  tongue. 

The  glosso-pharyngeal  portion  of  the  eighth  pair, 
sending  off  several  branches  in  its  course,  passes  to  the 
tongue  near  its  basis,  and  divides  into  many  small 
branches,  which  are  spent  upon  the  sides  and  middle  of 
the  root  of  the  tongue,  and  also  upon  the  large  papillae:. 

The  ninth  pair  of  nerves  are  principally  appropriated 
to  the  tongue.  They  pass  on  each  side  to  the  most  fleshy 
part  of  it,  and  after  sending  one  branch  to  the  mylo-hyoi- 
deus,  and  another  to  communicate  with  the  lingual  branch 
of  the  fifth  pair,  they  are  spent  principally  upon  the  ge- 
nio-glossi,  and  linguales  muscles. 

The  tongue  answers  a threefold  purpose.  It  is  the 
principal  organ  of  taste.  It  is  a very  important  agent  in 
the  articulation  of  words;  and  it  assists  in  those  operations 
upon  our  food,  which  are  performed  in  the  mouth. 

The  Salivary  Glands. 

The  salivary  glands  have  such  an  intimate  connexion 
with  the  mouth  that  they  may  be  described  with  it.* 

There  are  three  principal  glands  on  each  side:  the  Paro- 
tid, the  Submaxillary  and  the  Sublingual.  They  are  of  a 
whitish  or  pale  flesh-colour,  and  are  composed  of  many 
small  united  masses  or  lobuli,  each  of  which  sends  a small 


For  a general  account  of  glands,  sec  the  appendix  to  this  volume 


25 


Parotid  and  Submaxillary  Glands. 

excretory  duct  to  join  similar  ducts  from  the  other  lobuli, 
and  thereby  form  the  great  duct  of  the  gland. 

The  Parotid  is  much  larger  than  the  other  glands.  It 
occupies  a large  portion  of  the  vacuity  between  the  mas- 
toid process  and  the  posterior  parts  of  the  lower  jaw.  It 
extends  from  the  ear  and  the  mastoid  process  over  a por- 
tion of  the  masseter  muscle,  and  from  the  zygoma  to  the 
basis  of  the  lower  jaw.  Its  name  is  supposed  to  be  de- 
rived from  two  Greek  words  which  signify  contiguity  to 
the  ear.  It  is  of  a firm  consistence.  It  receives  branches 
from  the  external  carotid  artery  and  from  its  facial  branch. 

From  the  anterior  edge  of  this  gland,  rather  above  the 
middle,  the  great  duct  proceeds  anteriorly  across  the  mas- 
seter muscle;  and,  after  it  has  passed  over  it,  bends  inward 
through  the  adipose  matter  of  the  cheek  to  the  buccinator 
muscle,  which  it  perforates  obliquely  and  opens  on  the 
inside  of  the  cheek  opposite  to  the  interval  between  the 
second  and  third  molar  teeth  of  the  upper  jaw.  The  aper- 
ture of  the  duct  is  rather  less  than  the  general  diameter  of 
it,  and  this  circumstance  has  the  effect  of  a valve.  When 
the  duct  leaves  the  parotid,  several  small  glandular  bodies 
are  often  attached  to  it,  and  their  ducts  communicate 
with  it.  The  main  duct  is  sometimes  called  after  Steno, 
who  first  described  it. 

When  the  mouth  is  opened  wide,  as  in  gaping,  there 
is  often  a jet  of  saliva  from  it  into  the  mouth. 

The  parotid  gland  furnishes  the  largest  proportion  of 
saliva. 

It  covers  the  nerve  called  Port.i6  Dura , after  it  has 
emerged  from  the  foramen  stylo-mastoideum. 

The  second  gland  is  called  the  Sub  maxillary.  It  is 
much  smaller  than  the  parotid,  and  rather  round  in  form. 
It  is  situated  immediately  within  the  angle  of  the  lower 
jaw,  between  it,  on  the  outside,  and  the  tendon  of  the  di- 
gastric muscle  and  the  ninth  pair  of  nerves  internally.  Its 
ValJI.  D 


26 


Sublingual  Gland. — Saliva. 

posterior  extremity  is  connected  by  cellular  membrane  to' 
the  parotid  gland;  its  anterior  portion  lies  over  a part  of 
the  mylo-hyoideus  muscle;  and  from  it  proceeds  the  ex- 
cretory duet,  which  is  of  considerable  length,  and  passes 
betwen  the  mylo-hyoideus  and  the  genio-glossus  muscles 
along  the  under  and  inner  edge  of  the  sublingual  gland. 
In  this  course  the  duct  is  sometimes  surrounded  with 
small  glandular  bodies,  which  seem  to  be  appendices  of 
the  sublingual  gland.  It  terminates  under  the  tongue,  on 
the  side  of  the  fraenum  linguae,  by  a small  orifice  which 
sometimes  forms  a papilla. 

The  orifice  is  often  smaller  than  the  duct;  in  conse- 
quence of  which,  obstruction  frequently  occurs  here,  and 
produces  the  disease  called  ranula. 

The  sublingual  gland,  which  has  already  been  mention- 
ed, lies  so  that,  when  the  tongue  is  turned  up,  it  can  be 
seen  protruding  into  the  cavity  of  the  mouth,  and  co- 
vered by  the  lining  membrane,  which  seems  to  keep  it 
fixed  in  its  place.  It  lies  upon  the  mylo-hyoideus,  by  the 
side  of  the  genio-hyoideus;  and  is  rather  oval  in  form  and 
fiat.  Its  greatest  length  is  from  before  backwards;  its  po- 
sition is  rather  oblique,  one  edge  being  placed  obliquely 
inwards  and  upwards,  and  the  other  outwards  and  down- 
wards. It  has  many  short  excretory  ducts,  which  open  by 
orifices  arranged  in  a line  on  each  side:  they  are  discover- 
ed with  difficulty,  on  account  of  their  small  size,  and 
sometimes  amount  to  eighteen  or  twenty  in  number.  In 
some  few  instances,  this  gland  sends  off  a single  duct, 
which  communicates  with  the  duct  of  the  submaxillary 
gland. 

The  salivary  fluid  secreted  by  these  glands  is  inodo- 
rous, insipid,  and  limpid,  like  water;  but  much  more  vis- 
cid, and  of  greater  specific  gravity.  Water  constitutes  at 
least  four  fifths  of  its  bulk;  and  animal  mucus  one  half  of 
its  solid  contents.  It  also  contains  some  albumen,  and 


27 


Motions  of  the  Tongue. 

several  saline  substances:  as  the  muriate  of  soda,  and  the 
phosphates  of  lime,  of  soda,  and  of  ammonia. 

It  is  probable  that  this  fluid  possesses  a solvent  power 
with  respect  to  the  articles  of  food. 

There  are  small  glandular  bodies,  situated  between  the 
masseter  and  buccinator  muscles,  opposite  to  the  last  mo- 
lar tooth  of  the  upper  jaw,  whose  nature  is  not  well  under- 
stood: they  are  called  Glandules  Molares. 

The  motions  of  the  tongue  are  very  intelligible  to  a per- 
son who  has  a preparation  of  the  lower  jaw  before  him, 
with  the  tongue  in  its  natural  situation,  and  the  mus- 
cles, which  influence  it,  properly  dissected.  Its  compli- 
cated movements  will  appear  the  necessary  result  of  the 
action  of  those  muscles  upon  it,  and  the  os  hyoides;  and 
also  upon  the  larynx,  with  which  the  os  hyoides  is  con- 
nected. The  muscular  fibres  of  the  tongue  itself  are  also 
to  be  taken  into  this  view,  as  they  act  a very  important 
part. 

Although  the  tongue  appears  very  necessary,  in  a me- 
chanical point  of  view,  to  the  articulation  of  many  words, 
yet  there  are  cases  where  it  has  been  entirely  deficient, 
in  which  the  parties,  thus  affected,  have  been  able  to 
speak  very  well  in  general,  as  well  as  to  distinguish  dif- 
ferent tastes.^ 

The  tongue  is  also  a very  delicate  organ  of  touch.  We 
can  perceive  the  form  of  the  teeth,  and  the  state  of  the 
surface  of  the  mouth,  more  accurately  by  the  applica- 
tion of  the  tongue  than  of  the  fingers. 

♦There  is  a very  interesting  paper  on  this  subject,  in  the  Memoirs 
of  the  Academy  of  Sciences  far  the  year  1718,  by  Jussieu ; in  which 
he  describes  the  case  of  a female,  fifteen  years  old,  examined  by 
himself,  who  was  born  without  a tongue.  In  this  paper  he  refers  to 
another  case,  described  by  Rolland,  a surgeon  of  Saumur,  of  a boy 
nine  years  old,  whose  tongue  was  destroyed  by  gangrene.  In  each 
of  these  cases  the  subject  was  able  to  articulate  very  well,  with  the 
exception  of  a few  letters:  and  also  enjoyed  the  sense  of  taste. 


Observations  on  the  Tongue . 

Of  the  three  nerves  which  go  to  the  tongue,  it  is  generally 
supposed  that  the  lingual  portion  of  the  third  branch  of 
the  fifth  pair  is  most  immediately  concerned  in  the  func- 
tion of  tasting,  as  it  passes  to  the  front  part  of  the  sur- 
face of  the  tongue.  The  glosso-pharyngeal  are  probably 
concerned  in  the  same  function  on  the  posterior  part, 
while  the  ninth  pair  of  nerves  seems  principally  spent 
upon  the  muscular  parts  of  the  organ. 

It  is  obvious  that  the  tongue  is  most  copiously  supplied 
with  nerves.  This  probably  accounts  for  the  great  faci- 
lity of  its  motions,  and  the  power  of  continuing  them. 


29 


CHAPTER  III. 

OF  THE  THROAT. 

TO  avoid  circumlocution,  the  word  throat  is  used  as  a 
general  term  to  comprehend  the  structure  which  occurs 
behind  the  nose  and  mouth,  and  above  the  oesophagus 
and  trachea.  This  structure  consists, 

1st,  Of  the  parts  immediately  behind  the  mouth,  which 
constitute  the  Isthmus  of  the  Fauces: 

2d,  Of  the  parts,  which  form  the  orifice  of  the  wind- 
pipe, or  the  Larynx;—* and 

3d,  Of  the  muscular  bag,  which  forms  the  cavity  be- 
hind  the  nose  and  mouth  that  terminates  in  the  oesophagus, 
or  the  Pharynx, 


SECTION  I. 

Of  the  Isthmus  of  the  Fauces. 

In  the  back  part  of  the  mouth,  on  each  side,  are  to  be 
seen  the  two  ridges  or  half  arches,  passing  from  the  soft 
palate  to  the  root  of  the  tongue,  mentioned  in  page  17, 
and  said  to  be  formed  by  plaits  of  the  skin  containing 
muscular  fibres.  The  anterior  plait,  which  contains  the 
muscle  called  Constrictor  Isthmi  Faucium , passes  directly 
from  the  side  of  the  root  of  the  tongue  to  the  palate,  and 
terminates  near  the  commencement  of  the  uvula.  The 
posterior  plait  runs  from  the  palate  obliquely  downwards 
and  backwards,  as  it  contains  the  palato-pharyngeus  mus- 
cle, which  passes  from  the  palate  to  the  upper  and  pos- 
terior part  of  the  thyroid  cartilage. 


30 


Tonsils. — Epiglottis. 

In  the  triangular  space  between  these  ridges  is  situated 
a glandular  body,  called  the  Tonsil  or  Amygdala.  This 
gland  has  an  oval  form,  its  longest  diameter  extending 
from  above  downwards.  Its  surface  is  rather  convex,  its 
natural  colour  is  a pale  red.  On  its  surface  are  the  large 
orifices  of  many  cells  of  considerable  size,  which  exist 
throughout  the  gland.  These  cells  often  communicate 
with  each  other,  so  that  a probe  can  be  passed  in  at  one 
orifice  and  out  at  the  other. 

Into  these  cells  open  many  mucous  ducts,  which  dis- 
charge the  mucus  of  the  throat,  for  the  purpose  of  lubri- 
cating the  surface,  and  facilitating  the  transmission  of 
food. 

The  epiglottis,  or  fifth  cartilage  of  the  larynx,  is  situa- 
ted at  the  root  of  the  tongue,  in  the  middle,  between  the 
tonsils.  The  part  which  is  in  sight  is  partly  oval  in  form, 
and  of  a whitish  colour.  Its  position,  as  respects  the 
tongue,  is  nearly  perpendicular,  and  its  anterior  surface 
rather  convex. 

The  membrane  continued  from  the  tongue  over  the 
epiglottis  is  so  arranged  that  it  forms  a plait,  which  ex- 
tends from  the  middle  of  the  root  of  the  tongue  along  the 
middle  of  the  anterior  surface  of  the  epiglottis,  from  its 
base  upwards. 

On  each  side  of  this  plait,  or  fraenum,  at  the  junction 
of  the  surfaces  of  the  tongue  and  of  the  epiglottis,  there 
is  often  a depression,  in  which  small  portions  of  food 
sometimes  remain;  and  a small  fraenum,  similar  to  that 
above  described,  is  sometimes  seen  on  the  outside  of  each 
of  these  cavities. 

The  epiglottis  is  situated  immediately  before  the  open- 
ing into  the  larynx. 

The  above  described  parts  can  be  well  ascertained  in 
the  living  subject,  by  a person  who  Iras  a general  know- 
ledge of  the  structure.  Thus,  looking  into  the  mouth, 


Of  the  Larynx.  31 

with  the  tongue  depressed,  the  uvula  and  soft  palate  are 
in  full  view  above,  and  the  epiglottis  is  very  perceptible 
below;  while  the  two  ridges  or  lateral  half-arches  can  be 
seen  on  each  side,  with  the  tonsil  between  them. 


SECTION  II. 

Of  the  Larynx. 

IN  this  structure  are  five  cartilages,  upon  which  its 
form  and  strength  depends,  viz:  the  Cricoid,  the  Thyroid, 
the  two  Arytenoid,  and  the  Epiglottis.  These  cartilages 
are  articulated  to  each  other,  and  are  supplied  with  mus- 
cles by  which  certain  limited  motions  are  effected. 

The  basis  of  the  structure  is  a cartilaginous  ring,  called 
the  cricoid  cartilage,  which  may  be  considered  as  the  com- 
mencement of  the  windpipe. 

It  may  be  described  as  an  irregular  section  of  a tube: 
its  lower  edge,  connected  with  the  windpipe,  being  nearly 
horizontal  when  the  body  is  erect;  and  the  upper  edge 
very  oblique,  sloping  from  before,  backwards  and  up- 
wards: in  consequence  of  this,  it  has  but  little  depth  be- 
fore, but  is  eight  or  nine  lines  deep  behind. 

The  Thyroid  cartilage  is  a single  plate,  bent  in  such 
manner  that  it  forms  an  acute  angle  with  two  similar 
broad  surfaces  on  each  side  of  it.  It  is  so  applied  to  the 
cricoid  cartilage,  that  the  lower  edge  of  the  angular  part 
is  at  a small  distance  above  the  front  part  of  that  car- 
tilage, and  connected  to  it  by  ligamentous  membrane: 
while  its  broad  sides  are  applied  to  it  laterally,  and  thus 
partially  inclose  it. 

The  upper  edge  of  the  angular  part  of  the  thyroid  car- 
tilage forms  a notch;  and  the  natural  position  of  the  carti- 


32  Arytenoid  Cartilages  and  Ligaments. 

lage  is  such,  that  this  part  is  very  prominent  in  the  neck: 
it  is  called  the  Pomum  Adami. 

Both  the  upper  and  lower  edges  of  the  thyroid  cartilage 
terminate  posteriorly  in  processes,  which  are  called  Cor- 
nua. The  two  uppermost  are  longest:  they  are  joined  by 
ligaments  to  the  extremities  of  the  os  hyoides.  The  lower 
and  shorter  processes  are  fixed  to  the  cricoid  cartilage. 
The  thyroid  cartilage,  therefore,  partly  rests  upon  the 
cricoid  cartilage  below,  and  is  attached  to  the  os  hyoides 
above.  It  is  influenced  by  the  muscles  which  act  upon  the 
os  hyoides,  and  also  by  some  muscles  which  are  inserted 
into  itself.  It  is  moved  obliquely  downwards  and  forwards, 
in  a slight  degree,  upon  the  cricoid  cartilage  by  a small 
muscle,  the  crico-thyroideus,  which  arises  from  that  car- 
tilage and  is  inserted  into  it. 

The  Arytenoid  cartilages  are  two  small  bodies  of  a tri- 
angular pyramidal  form,  but  slightly  curved  backwards. 
They  are  placed  upon  the  upper  and  posterior  edge  of  the 
cricoid  cartilage,  near  to  each  other;  and  their  upper  ends, 
taken  together,  resemble  the  mouth  of  a pitcher  or  ewer; 
from  which  circumstance  their  name  is  derived.  Their 
bases  are  broad;  and  on  their  lower  surfaces  is  a cavity, 
which  corresponds  with  the  convex  edge  of  the  cricoid 
cartilage,  to  which  they  are  applied.  At  these  places,  a 
regular  moveable  articulation  is  formed,  by  a capsular 
ligament  between  each  of  these  cartilages  and  the  thyroid; 
in  consequence  of  which  they  can  be  inclined  backward  or 
forward,  inward  or  outward. 

From  the  anterior  part  of  each  of  these  cartilages,  near 
the  base,  a tendinous  cord  passes  forward,  in  a direction 
which  is  horizontal  when  the  body  is  erect,  to  the  internal 
surface  of  the  angle  of  the  thyroid.  These  ligaments  are 
not  perfectly  parallel  to  each  other;  for  they  are  nearer  be- 
fore than  behind.  The  aperture  between  them  is  from  two 
to  five  lines  wide  when  the  muscles  are  not  in  action;  and 


Epiglottis.  33 

this  aperture  is  the  orifice  of  the  windpipe:  for  the  exte- 
rior space,  between  these  ligaments  and  the  circumference 
of  the  cricoid,  is  closed  up  by  membrane  and  muscle.  At 
a small  distance  above  these  ligaments  are  two  others, 
which  also  pass  from  the  arytenoid  to  the  thyroid  carti- 
lages. They  are  not  so  tendinous  and  distinct  as  the  first 
mentioned,  and  cannot  be  drawn  so  tense  bv  the  muscles 
of  the  arytenoid  cartilages.  They  are  also  situated  at  a 
greater  distance  from  each  other,  and  thus  form  a large 
aperture. 

On  the  external  side  of  the  upper  extremity  of  each  of 
the  arytenoid  cartilages,  and  nearly  in  contact  with  it,  is  a 
small  cartilaginous  body,  not  so  large  as  a grain  of  wheat, 
and  nearly  oval  in  form.  These  are  connected  firmly  to 
the  arytenoid  cartilages,  and  are  called  their  appendices . 
Being  in  the  margin  of  the  aperture  of  the  larynx,  they 
have  an  effect  upon  its  form. 

The  arytenoid  cartilages  are  the  posterior  parts  of  the 
larynx:  the  Epiglottis , which  has  already  been  mentioned, 
is  the  anterior.  When  this  cartilage  is  divested  of  its  mem- 
brane, it  is  oval  in  its  upper  extremity,  and  rather  angular 
below,  terminating  in  a long  narrow  process  which  is  like 
the  stalk  of  a leaf.  It  is  firmly  attached  to  the  internal  surface 
of  the  angular  part  of  the  thyroid  by  this  lower  process; 
and,  being  placed  in  a perpendicular  position,  one  of  its 
broad  surfaces  is  anterior  towards  the  tongue,  and  the 
other  posterior,  towards  the  opening  of  the  windpipe. 

It  is  attached  to  the  os  hyoides  by  dense  cellular  texture 
or  ligament,  and  to  the  tongue  by  .those  plaits  of  the  mem- 
brane of  the  mouth,  which  have  been  already  described. 

It  is  elastic,  but  more  flexible  than  the  other  cartilages; 
being  somewhat  different  in  its  structure.  Its  surface  is 
perforated  by  the  orifices  of  many  mucous  ducts. 

There  is  a small  space  between  the  lower  part  of  this 
cartilage  which  is  posterior,  and  the  upper  part  of  the  thy- 
roid and  the  ligament  passing  from  it  to  the  os  hyoides, 
Vol.  II.  E 


34 


Rima.  Glottidis. — Glottis. 


which  air  anterior.  In  this  is  a substance,  which  appears 
to  consist  of  glandular  and  of  adipose  matter.  It  is  suppo- 
sed that  some  of  the  orifices  on  the  lower  part  of  the  epi- 
glottis communicate  with  this  substance. 

In  the  erect  position  of  the  body,  the  epiglottis  is  situa- 
ted rather  higher  up  than  the  arytenoid  cartilages,  and  at 
the  distance  of  ten  or  twelve  lines  from  them. 

The  membrane  which  covers  the  epiglottis,  is  extended 
from  each  side  of  it  to  the  arytenoid  cartilages;  and  being 
continued  into  the  cavity  of  the  larynx,  as  well  as  upon  the 
general  surface  of  the  throat,  it  is  necessarily  doubled: 
this  doubling  forms  the  lateral  margins  of  the  orifice  of  the 
cavity  of  the  larynx.  In  these  folds  of  the  membrane  are 
seen  very  delicate  muscular  fibres,  called  the  Aryteno-epi- 
glottidei. 

The  membrane  continues  down  the  cavity  of  the  la- 
rynx, and,  covering  the  upper  ligaments,  penetrates  into 
the  vacuity  between  them  and  the  lower  ligaments,  so  as 
to  form  a cavity  on  each  side  of  the  larynx,  opening  be- 
tween the  two  ligaments,  which  is  called  the  Ventricle  of 
Morgagni.  The  shape  of  these  cavites  is  oblong.  Its  great- 
est length  extends  from  behind  forward,  on  each  side  of 
the  opening  into  the  windpipe  formed  by  the  two  lower 
or  principal  ligaments;  so  that  when  the  larynx  is  re- 
moved from  the  subject,  upon  looking  into  it  from  above, 
you  perceive  three  apertures:  one  in  the  middle,  formed 
by  the  two  lower  ligaments;  and  one  on  each  side  of  it, 
between  the  lower  and  upper  ligament,  which  is  the  ori- 
fice of  the  ventricle  of  Morgagni. 

The  aperture  between  the  two  lower  ligaments  is  called 
the  Rima  Glottidis , or  Chink  of  the  Glottis;  the  upper  aper- 
ture, formed  by  the  fold  of  the  membrane  extending  from 
the  epiglottis  to  the  arytenoid  cartilages,  may  be  termed 
Glottis. 

If  the  windpipe  is  divided  near  the  larynx,  and  the  la- 
rynx inverted,  so  that  the  rima  glottidis  may  be  examined 


35 


Arteries  and  Nerves  of  the  Larynx. 

from  below,  the  structure  appears  still  more  simple:  it 
resembles  a septum  fixed  abruptly  in  the  windpipe,  with 
an  aperture  in  it  of  the  figure  of  the  rima  glottidis. 

The  anterior  surface  of  the  two  arytenoid  cartilages  is 
concave.  This  concavity  is  occupied  in  each  by  a glandu- 
lar substance,  which  lies  between  the  cartilage  and  the 
lining  membrane;  and  extends  itself  horizontally,  covered 
by  the  upper  ligament  of  the  glottis.  The  nature  of  these 
bodies  is  not  perfectly  understood;  but  they  are  supposed 
to  secrete  mucus. 

The  membrane,  which  lines  the  cavity  of  the  glottis, 
being  continued  from  the  mouth  and  throat,  resembles  the 
membranes  which  invest  those  parts.  In  some  places, 
where  it  is  in  close  contact  with  the  cartilages,  it  appears 
united  with  the  perichondrium,  and  acquires  more  firm- 
ness and  density. 

The  general  motions  of  the  larynx  are  very  intelligible 
to  those  who  are  acquainted  with  the  muscles  which  are 
connected  with  the  thyroid  cartilage,  and  which  move  the 
os  hyoides.  They  take  place  particularly  in  deglutition, 
and  in  some  modifications  of  the  voice;  and  also  in  vomit- 
ing. 

The  motions  of  the  particular  cartilages  on  each  other 
can  also  be  well  understood,  by  attending  to  the  origin  and 
insertion  of  the  various  small  muscles  connected  with 
them.  The  most  important  of  these  muscles  are  the  crico^ 
arytenoidei  postici  and  laterales,  the  thyreo-arytenoidei, 
the  arytenoidei  obliqui,  and  the  arytenoideus  transversus. 
The  effects  of  their  actions  appear  to  be  the  dilating  or 
contracting  the  rima  glottidis,  and  relaxing  or  extending 
the  ligaments  which  form  it. 

The  arteries  of  the  larynx  are  derived  from  two  sources, 
viz:  the  superior  thyroid,  or  laryngeal  branch  of  the  ex- 
ternal carotid;  and  the  thyroid  branch  of  the  subclavian. 

The  nerves  of  the  larynx  also  come  to  it  in  two  very  dif- 
ferent directions  on  each  side.  It  receives  two  branches 


36 


The  Thyroid  Gland. 

from  the  par  vagum:  one  which  leaves  that  nerve  high  up 
in  the  neck,  and  is  called  the  Superior  Laryngeal  branch; 
and  another  which  proceeds  from  it  after  it  has  passed 
into  the  cavity  of  the  thorax,  and  is  called  from  its  direc- 
tion the  Recurrent. 

The  extreme  irritability  of  the  glottis  is  unequivocally 
demonstrated  by  the  cough  which  is  excited  when  a 
drop  of  water,  or  any  other  mild  liquid,  or  a crumb  of 
bread  enters  it.  Notwithstanding  this,  a flexible  tube, 
or  catheter,  has  several  times  been  passed  into  the 
windpipe  through  the  rima  glottidis,  and  been  endured 
by  the  patient  a considerable  time. 

The  cough,  which  occurs  when  these  parts  are  irritated, 
does  not  appear  to  arise  exclusively  from  the  irritation 
of  the  membrane  within  the  glottis;  for,  if  it  were 
so,  mucilaginous  substances,  when  swallowed  slowly, 
could  not  suspend  it.  Their  effect  in  relieving  cough 
is  universally  known;  and  as  they  are  only  applied  to 
the  surface  exterior  to  the  glottis,  it  is  evident  that  the 
irritation  of  this  surface  must  also  produce  coughing. 

Several  curious  experiments  have  been  made  to  deter- 
mine the  effect  of  dividing  the  different  nerves  which 
go  to  the  larynx;  by  which  it  appears  that  the  recurrent 
branches  supply  parts  which  are  essentially  necessary 
to  the  formation  of  the  voice,  whilst  the  laryngeal 
branches  supply  parts  which  merely  influence  its  modula- 
tion, or  tone.  See  Mr.  Haighton’s  Essay  on  this  subject; 
Memoirs  of  the  Medical  Society  of  London,  Vol.  III. 

The  Thyroid  Gland 

May  be  described  here,  although  a part  of  it  is  situated 
below  the  larynx. 

This  body  consists  of  two  lobes,  which  are  united  at 
their  lower  extremities  by  a portion  which  extends  across 
the  anterior  part  of  the  windpipe.  Each  lobe  generally 
rises  upwards  and  backwards  from  the  second  cartilagi- 
nous ring  of  the  windpipe  over  the  cricoid  cartilage  and 
a portion  of  the  thyroid.  It  lies  behind  the  sterno-hyoidei 


37 


Of  the  Pharynx . 

and  sterno-thyroidei  muscles.  It  is  of  a reddish  brown 
colour,  and  appears  to  consist  of  a granulous  substance; 
but  its  ultimate  structure  is  not  understood.  It  is  plenti- 
fully supplied  with  blood,  and  receives  two  arteries  on 
each  side:  one  from  the  laryngeal  branch  of  the  external 
carotid:  and  the  other  from  the  thyroid  branch  of  the 
subclavian. 

Notwithstanding  this  large  supply  of  blood,  there  is  no 
proof  that  it  performs  any  secretion;  for  although  several 
respectable  anatomists  have  supposed  that  they  discover- 
ed excretory  ducts  passing  to  the  windpipe,  larynx,  or 
tongue,  it  is  now  generally  agreed  that  such  excretory 
ducts  are  not  to  be  found.  Several  instances  have  how- 
ever occurred,  in  which  air  has  been  forced,  by  violent 
straining,  from  the  windpipe  into  the  substance  of  this 
gland. 


SECTION  III. 

Of  the  Pharynx. 

THE  pharynx  is  a large  muscular  bag,  which  formr; 
the  great  cavity  behind  the  nose  and  mouth  that  termi- 
nates  in  the  oesophagus. 

It  has  been  compared  to  a funnel,  of  which  the  oeso- 
phagus is  the  pipe;  but  it  differs  from  a funnel  in  this 
respect,  that  it  is  incomplete  in  front,  at  the  part  occu- 
pied by  the  nose  and  mouth  and  larynx. 

It  is  connected  above,  to  the  cuneiform  process  of  the 
occipital  bone,  to  the  pterygoid  processes  of  the  sphenoi 
dal,  and  to  both  the  upper  and  lower  maxillary  bones.  It 
is  in  contact  with  the  cervical  vertebrae  behind;  and,  op- 
posite to  the  cricoid  cartilage,  it  terminates  in  the  oeso- 
phagus. 

t 


38 


Structure  of  the  Pharynx. 


If  the  pharynx  and  oesophagus  be  carefully  dissected 
and  detached  from  the  vertebras,  preserving  the  con- 
nexion of  the  pharynx  with  the  head;  and  the  head  then 
be  separated  from  the  body,  by  dividing  the  articulation 
of  the  atlas  and  the  os  occipitis,  and  cutting  through  the 
soft  parts  below  the  larynx;  the  resemblance  to  a funnel 
will  be  very  obvious. 

In  this  situation,  if  an  incision  be  made  from  above 
downwards  through  the  whole  extent  of  the  posterior 
part  of  the  pharynx,  the  communication  of  the  nose, 
mouth,  and  windpipe,  with  this  cavity,  will  be  seen  from 
behind  at  one  view. 

The  openings  into  the  nose,  or  the  posterior  nares,  ap- 
pear uppermost.  Their  figure  is  irregularly  oval  or  ob- 
long: they  are.  separated  from  each  other  by  a thin  parti- 
tion, the  vomer.  Immediately  behind,  on  the  external 
side  of  each  of  these  orifices,  is  the  Eustachian  tube. 

The  soft  palate  will  appear  extending  from  the  lower 
boundary  of  the  posterior  nares,  obliquely  backward  and 
downwards,  so  as  nearly  to  close  the  passage  into  the 
mouth.  The  uvula  hangs  from  it;  and,  on  each  side  of  the 
uvula,  the  edge  of  the  palate  is  regularly  concave. 

Below  the  palate,  in  the  isthmus  of  the  fauces,  are  the 
ridges  or  half-arches,  and  the  tonsils  between  them.  The 
half-arch  which  presents  first,  in  this  view,  runs  ob- 
liquely downward  and  backward,  and  not  parallel  to  the 
other. 

Close  to  the  root  of  the  tongue  is  the  epiglottis  erect; 
and,  immediately  adjoining  it,  is  an  aperture  large  enough 
to  admit  the  end  of  a middle-sized  finger.  This  aperture 
is  widest  at  the  extremity  next  to  the  epiglottis,  and  rather 
narrower  at  the  other  extremity:  it  is  the  glottis  or  open- 
ing of  the  windpipe.  When  the  larynx  is  elevated,  the 
epiglottis  can  be  readily  depressed  so  as  to  cover  it  com- 
pletely. 

The  extremities  of  the  arytenoid  cartilages,  and  their 


39 


Structure  of  the  Pharynx. 

appendices,  may  be  recognised  at  the  posterior  edge  of 
the  glottis.  At  a short  distance  below  this  edge,  the  oeso- 
phagus begins. 

The  Pharynx  is  composed  of  the  membrane  continued 
from  the  nose  and  mouth  internally,  and  of  a stratum  of 
muscular  fibres  externally.  The  internal  membrane  is 
very  soft  and  flexible,  and  perforated  by  many  mucife- 
rous  ducts.  The  surface  which  it  forms  is  rather  rough, 
owing  to  the  mucous  glands  which  it  covers.  It  has  a red 
colour,  but  not  so  deep  as  that  of  some  other  parts.  It  is 
connected  to  the  muscular  stratum  by  a loose  cellular 
membrane. 

The  muscular  coat  consists  of  three  different  portions, 
which  are  considered  as  so  many  distinct  muscles. 

The  fibres  of  each  of  these  muscles  originate  on  each 
side,  and  run  in  an  oblique  direction  to  meet  in  the  mid- 
dle, thus  forming  the  posterior  external  surface  of  the 
dissected  pharynx. 

The  fibres  of  the  upper  muscle  originate  from  the  cu- 
neiform process  of  the  occipital  bone,  from  the  pterygoid 
processes  of  the  os  sphenoides,  and  from  the  upper  and 
lower  jaws,  near  the  last  dentes  molares,  on  each  side. 
They  unite  in  a middle  line  in  the  back  of  the  pharynx. 

The  fibres  of  the  middle  muscle  originate  principally 
from  the  lateral  parts  of  the  os  hyoides,  and  from  the  liga- 
ments which  connect  that  bone  to  the  thyroid  cartilage. 
The  superior  fibres  run  obliquely  upwards,  so  as  to 
cover  a part  of  the  first  mentioned  muscle,  and  terminate 
in  the  cuneiform  process  of  the  occipital  bone;  while  the 
other  fibres  unite  with  those  of  the  opposite  side  in  the 
middle  line. 

The  fibres  of  the  lower  muscles  arise  from  the  thyroid 
and  the  cricoid  cartilages,  and  terminate  also  in  the  mid- 
dle line.  Those  which  are  superior,  running  obliquely 
upwards;  the  inferior,  nearly  in  a transverse  direction. 


40  Structure  of  the  Pharynx. 

It  is  obvious,  from  the  origin  and  insertion  of  these 
fibres,  that  the  pharynx  must  have  the  power  of  contract- 
ing its  dimensions  in  every  respect;  and,  particularly,  that 
its  diameter  may  be  lessened  at  any  place;  and  that  the 
whole  may  be  drawn  upwards. 


SYSTEM  OF  ANATOMY. 


PART  vii. 


OF  THE  THORAX. 

BEFORE  the  thorax  is  described,  it  will  be  in  order  to 
consider  the 

Mamma; 

Or  those  glandular  bodies,  situated  on  the  anterior  part 
of  it,  which,  in  females,  are  destined  to  the  secretion  of 
milk. 

These  glands  lie  between  the  skin  and  the  pectoral  mus- 
cles, and  are  attached  to  the  surfaces  of  those  muscles  by 
cellular  membrane. 

They  are  of  a circular  form;  and  consist  of  a whitish 
firm  substance,  divisible  into  small  masses  or  lobes,  which 
are  composed  of  smaller  portions  or  lobuli.  Between  these 
glandular  portions  a great  deal  of  adipose  matter  is  so  dif- 
fused, that  it  constitutes  a considerable  part  of  the  bulk  of 
the  mammas. 

The  gland  however,  varies  greatly  in  thickness  in  the 
same  person  at  different  periods  of  life. 

The  mammae  become  much  enlarged  about  the  age  of 
puberty.  They  are  also  very  large  during  pregnancy  and 
Vol.  II.  F 


42 


Mamma. 


lactation;  but  after  the  period  of  childbearing,  they  dimi- 
nish considerably.  They  are  supplied  with  blood  by  the 
external  and  internal  mammary  arteries,  the  branches  of 
which  enter  them  irregularly  in  several  different  places. 

The  veins  correspond  with  the  arteries. 

From  the  small  glandular  portions  that  compose  the 
mamma,  fine  excretory  tubes  arise,  which  unite  together 
and  form  the  great  lactiferous  ducts  of  the  gland.  These 
ducts  proceed  in  a radiated  manner  from  the  circumfer- 
ence to  the  center,  and  terminate  on  the  surface  of  the 
nipple. 

They  are  commonly  about  fifteen  in  number,  and  vary 
considerably  in  size:  the  largest  of  them  being  more  than 
one  sixth  of  an  inch  in  diameter. 

They  can  be  very  readily  injected  by  the  orifices  of  the 
nipple,  from  a pipe  filled  with  mercury,  in  subjects  who 
have  died  during  lactation  or  pregnancy;  but  they  are  very 
small  in  subjects  of  a different  description. 

It  has  been  asserted,  by  respectable  anatomists,  that 
these  ducts  communicate  freely  with  each  other;  but  they 
do  not  appear  to  do  so:  each  duct  seems  to  be  connected 
with  its  proper  branches  only. 

Haller  appears  to  have  entertained  the  remarkable  sen- 
timent, that  some  of  the  ducts  originated  in  the  adipose 
matter  about  the  gland,  as  well  as  in  the  glandular  sub- 
stance.* 

The  papilla,  or  nipple,  in  which  these  ducts  terminate, 
is  in  the  center  of  the  mamma:  it  consists  of  a firm  elastic 
substance,  and  is  nearl)  cylindrical  in  form.  It  is  rendered 
tumid  by  irritation,  and  by  certain  emotions. 

The  lactiferous  ducts  terminate  upon  its  extremity. 
When  it  is  elongated,  they  can  freely  discharge  their  con- 
tents; but  when  it  contracts,  this  discharge  is  impeded. 

The  skin  immediately  around  the  nipple  is  of  a bright 

* Elements  Physiologic  Tom.  7,  Pars  1 1.  pag:  7. 


Mamma . 


43 


red  colour  in  virgins  of  mature  age.  In  pregnant  women 
it  is  sometimes  almost  black;  and  in  women  who  have 
borne  children  it  is  often  brownish.  It  abounds  with  seba- 
ceous glands,  which  form  small  eminences  on  its  surface. 

This  gland  exists  in  males,  although  it  is  very  small. 
In  boys,  soon  after  birth,  it  has  often  been  known  to 
tumify  and  become  very  painful,  in  consequence  of  the 
secretion  and  accumulation  of  a whitish  fluid,  which  can 
be  discharged  by  pressure.  It  also  sometimes  swells  and 
is  painful,  in  males  at  the  age  of  puberty. 

There  have  been  some  instances  in  which  it  has  secre- 
ted milk  in  adult  males;  and  a few  instances  also  in  which 
it  has  been  affected  with  cancer,  in  the  same  sex. 

The  mamma  is  plentifully  supplied  with  absorbent  ves- 
sels, which  pass  from  it  to  the  lymphatic  glands  in  the 
axilla. 

Its  nerves  are  principally  derived  from  the  great  plexus 
formed  by  the  nerves  of  the  arm.  . 


44 


CHAPTER  1. 

OF  THE  GENERAL  CAVITY  OF  THE  THORAX. 

SECTION  I. 

Of  the  form  of  the  Cavity  of  the  Thorax. 

THE  osseous  structure  of  the  thorax  is  described  in 
vol.  I.  page  83.  The  cavity  is  completed  by  the  intercostal 
muscles,  which  close  the  vacuities  between  the  ribs;  and 
by  the  diaphragm,  which  fills  up  the  whole  space  included 
within  its  lower  margin. 

If  we  except  the  apertures  of  the  diaphragm,  which  are 
completely  occupied  by  the  aorta,  the  vena  cava,  and  the 
oesophagus,  See.  the  only  outlet  of  this  cavity  is  above:  it  is 
formed  by  the  upper  ribs,  the  first  dorsal  vertebra,  and  the 
sternum.  The  figure  of  this  aperture  is  between  that  of 
the  circle  and  the  oval;  but  it  is  made  irregular  by  the  ver- 
tebra, and  by  the  upper  edge  of  the  sternum. 

When  the  superior  extremities  and  the  muscles  appro- 
priated to  them  are  removed,  the  external  figure  of  the 
thorax  is  conical;  but  the  cavity  formed  by  it  is  consi- 
derably influenced  by  the  spine,  which  protrudes  into  it; 
while  the  ribs,  as  they  proceed  from  the  spine,  curve  back- 
wards, and  thus  increase  its  prominency  in  the  cavity. 

The  diaphragm  has  a great  effect  upon  the  figure  of  the 
cavity  of  the  thorax.  It  protrudes  into  it  from  below,  with 
a convexity  of  such  form  that  it  has  been  compared  to  an 
inverted  bowl;  so  that,  although  it  arises  from  the  lower 
margin  of  the  thorax,  the  central  parts  of  it  are  nearly  as 
high  as  the  fourth  rib. 


Pleura. 


45 


The  position  of  the  diaphragm  is  also  oblique.  The  an- 
terior portion  of  its  margin,  being  connected  to  the  seventh 
and  eighth  ribs,  is  much  higher  than  the  posterior  portion, 
which  is  attached  to  the  eleventh  and  twelfth. 

In  consequence  of  the  figure  and  position  of  the  dia- 
phragm, the  form  of  the  cavity  of  the  thorax  resembles 
that  of  the  hoof  of  the  ox  when  its  posterior  part  is  pre- 
sented forwards. 


SECTION  II. 

Of  the  arrangement  of  the  Pleura. 

THE  thorax  contains  the  two  lungs  and  heart,  as  well 
as  several  very  important  parts  of  smaller  size. 

The  lungs  occupy  the  greatest  part  of  the  cavity;  and  to 
each  of  them  is  appropriated  a complete  sac,  called  Pleura , 
which  is  so  arranged  that  it  covers  the  surface  of  the  lungs, 
and  is  continued  from  it  to  the  contiguous  surface  of  the 
thorax,  which  it  lines.  After  covering  the  lung,  it  is  ex- 
tended from  it  to  the  spine  posteriorly,  and  the  sternum 
anteriorly:  so  that  in  tracing  the  pleura  in  a circular  di- 
rection, if  you  begin  at  the  sternum,  it  proceeds  on  the 
inside  of  the  ribs  to  the  spine;  at  the  spine  it  leaves  the 
surface  of  the  thorax,  and  proceeds  directly  forwards 
towards  the  sternum.  In  its  course  from  the  spine  to  the 
sternum,  it  soon  meets  with  the  great  branch  of  the  wind- 
pipe and  the  bloodvessels,  which  go  to  the  lung:  it  con- 
tinues on  these  vessels  and  round  the  lung  until  it  arrives 
at  the  anterior  side  of  the  vessels,  when  it  again  proceeds 
forwards  until  it  arrives  at  the  sternum.  Each  sac  being 
arranged  in  the  same  way,  there  is  a part  of  each  extended 
from  the  spine  to  the  sternum.  These  two  lamina  form 
the  great  vertical  septum  of  the  thorax,  called  Mediasti- 
num. They  are  situated  at  some  distance  from  each  other; 


46 


Mediastinum. 


and  the  heart,  with  its  investing  membrane  or  pericar- 
dium, is  placed  between  them. 

The  pericardium  is  also  a complete  sac  or  bladder, 
which,  after  covering  perfectly  the  surface  of  the  heart,  is 
extended  from  it  so  as  to  form  a sac,  which  lies  loose  about 
it,  and  appears  to  contain  it.  This  loose  portion  adheres 
to  those  parts  of  the  lamina  of  the  mediastinum  with 
which  it  is  contiguous;  and  thus  three  chambers  are  form- 
ed within  the  cavity  of  the  thorax:  one  for  each  lung,  and 
one  for  the  heart. 

The  two  laminae  of  the  pleura,  which  constitute  the 
mediastinum,  are  at  different  distances  from  each  other,  in 
different  places.  At  the  upper  part  of  the  thorax,  they  ap- 
proach each  other  from  the  internal  edges  of  the  first  ribs; 
and,  as  these  include  a space  which  is  nearly  circular,  the 
vacuity  between  these  laminae  is  necessarily  of  that  form, 
at  its  commencement  above. 

Here  therefore  is  a space  between  them  above,  which 
is  occupied  by  the  great  transverse  vein  that  carries  the 
blood  of  the  left  subclavian  and  the  left  internal  jugular 
to  the  superior  cava;  by  the  trachea;  by  the  oesophagus; 
and  by  the  subclavian  and  carotid  arteries,  as  they  rise 
from  the  curve  of  the  aorta.  This  space  is  bounded  below 
by  the  above  mentioned  curve  of  the  aorta. 

The  heart  and  pericardium  are  so  placed  that  there  is  a 
small  distance  between  them  and  the  sternum:  in  this 
space  the  two  laminae  of  the  mediastinum  are  very  near  to 
each  other;  and  cellular  substance  intervenes  between 
them.  This  portion  of  the  mediastinum  is  called  the  An- 
terior Mediastinum. 

Posteriorly,  the  heart  and  pericardium  are  also  at  a 
small  distance  from  the  spine;  and  here  the  laminae  of  the 
mediastinum  are  at  a greater  distance  from  each  other, 
and  form  a long  narrow  cavity  which  extends  down  the 
thorax  in  front  of  the  vertebrae:  this  is  called  the  Poste- 
rior Mediastinum.  It  contains  a considerable  portion  of 


47 


Preparation  of  the  Thorax. 

the  aorta  as  it  descends  from  its  curve,  the  oesophagus, 
the  thoracic  duct,  and  the  vena  azygos.  The  aorta  is  in 
contact  with  the  left  lamina,  and  can  often  be  seen  through 
it  when  the  left  lung  is  lifted  up. 

The  oesophagus,  is  in  contact  with  the  right  lamina:  in 
its  progress  downwards,  it  inclines  to  the  left  side  and  is 
advanced  before  the  aorta. 

The  vena  azygos  appears  posterior  to  the  oesophagus: 
it  proceeds  upwards  untii  it  is  as  high  as  the  right  branch 
of  the  windpipe:  here  it  bends  forward,  round  that  branch, 
and  opens  into  the  superior  cava,  before  that  vein  opens 
into  the  right  auricle. 

The  thoracic  duct  proceeds  upwards  from  below,  lying 
in  the  spine  between  the  aorta  and  the  vena  azyrgos?  until 
the  beginning  of  the  curve  of  the  aorta,  when  it  inclines 
to  the  left,  proceeding  towards  the  place  of  its  termination. 

The  formation  of  the  mediastinum,  and  the  arrangement 
of  the  pleura,  as  well  as  the  connexion  of  these  mem- 
branes with  the  parts  contained  in  the  thorax,  may  be 
studied  advantageously,  after  the  subject  has  been  pre- 
pared in  the  manner  now  to  be  described. 

Take  away,  from  each  side,  the  five  ribs  which  are  situated 
between  the  first  and  last  true  ribs,  by  separating  their 
cartilages  from  the  sternum,  and  their  heads  from  the 
spine;  so  that  the  great  cavities  of  the  thorax  may  be  laid 
open. 

The  precise  course  of  the  mediastinum  is  thus  rendered  ob- 
vious; and  the  sternum  may  now  be  divided  with  a saw 
throughout  its  whole  length  in  the  same  direction;  so 
that  the  division  of  the  bone  may  correspond  with  the 
space  between  the  laminae  of  the  mediastinum. 

Separate  the  portions  of  the  sternum  cautiously,  so  as  to 
avoid  lacerating  the  laminae  of  the  mediastinum;  and 
keep  them  separate,  while  the  trachea  is  dissected  from 
the  neck  into  the  cavity  of  the  thorax;  the  great  trans- 
verse vein  and  the  descending  cava  are  dissected  to 
the  pericardium;  and  the  left  carotid  artery,  with  the 
right  subclavian  and  carotid,  are  dissected  to  the  curve 


48 


Preparation  of  the  Thorax . 

of  the  aorta,  taking  care  not  to  destroy  the  laminae  of  the 
mediastinum. 

After  this  preparation  the  upper  space  between  the  lami'nse 
of  the  mediastinum  can  be  examined;  and  the  relative 
situation  of  the  trachea  and  the  great  vessels  in  it  can  be 
understood.  The  anterior  mediastinum  can  also  be  stu- 
died:  the  root  of  each  lung,  or  its  connexion  with  the 
mediastinum,  may  be  seen  perfectly;  and  the  precise  si- 
tuation of  the  lung,  in  its  proper  cavity,  may  bewell  con- 
ceived. 

After  this,  while  the  portions  of  the  sternum  are  separated, 
the  pericardium  may  be  opened,  and  the  heart  brought 
into  view:  the  attachment  of  the  pericardium  to  the  me- 
diastinum, and  to  the  diaphragm,  may  be  seen  with  ad- 
vantage in  this  situation.  The  portions  of  the  sternum 
may  now  be  detached  from  the  ribs,  with  which  they  re- 
main connected;  and  further  dissection  may  be  perform- 
ed to  examine  the  posterior  mediastinum  and  its  contents, 
and  the  parts  which  constitute  the  roots  of  the  lungs. 


49 


CHAPTER  II. 

OF  THE  HEART  AND  THE  PERICARDIUM.  AND  THE  GREAT 
VESSELS  CONNECTED  WITH  THE  HEART. 

SECTION  II. 

Of  the  Pericardium. 

The  heart  is  inclosed  by  a membranous  sac,  which, 
upon  a superficial  view,  seems  only  connected  with  its 
great  vessels;  but  which,  in  fact,  adheres  closely  to  the 
whole  of  its  surface.  From  this  surface  it  is  extended  to 
those  vessels;  from  which  it  proceeds,  after  the  manner  of 
the  reflected  membranes,  and  forms  an  inclosure  that  lies 
loosely  about  the  heart.  If  it  were  dissected  from  the 
heart,  without  laceration  or  wounding,  it  would  be  an 
entire  sac. 

The  pericardium,  thus  arranged,  is  placed  between  the 
two  laminae  of  the  mediastinum,  and  adheres  firmly  to 
them  where  they  are  contiguous  to  it:  it  also  adheres 
firmly  to  the  diaphragm  below,  and  thus  preserves  the 
heart  in  its  proper  position. 

The  figure  of  the  pericardium,  when  it  is  distended,  is 
somewhat  conical;  the  base  being  on  the  diaphragm.  The 
cavity  formed  by  it  is  larger  than  the  heart  after  death, 
but  it  is  probable  that  the  heart  nearly  fills  it  during  life; 
for,  when  this  organ  is  distended  b}r  injection,  it  often  oc- 
cupies the  whole  cavity  of  the  pericardium. 

The  pericardium  is  composed  of  two  laminae,  the  inter- 
nal of  which  covers  the  heart,  as  has  been  already  descri- 
bed; while  the  external  merely  extends  over  the  loosfe  por- 
tion of  the  other,  and  blends  itself  with  the  mediastinum, 
where  that  membrane  invests  the  great  vessels. 

Vol.  II.  G 


50 


Of  the  Heart. 

The  internal  surface  of  the  pericardium  is  very  smooth 
and  polished;  and  in  the  living  subject  is  constantly  moi  st- 
ened vvith  a fluid,  which  is  probably  effused  from  the  ex- 
halent  vessels  on  its  surface. 

The  quantity  of  this  fluid  does  not  commonly  exceed 
two  drams;  but  in  cases  of  disease  it  sometimes  amounts 
to  many  ounces.*  It  is  naturally  transparent,  but  slightly 
tinged  with  red  in  children,  and  yellow  in  old  persons.  It 
is  often  slightly  tinged  with  red  in  persons  who  have  died 
by  violence. 


SECTION  II. 

Of  the  Heart. 

THE  great  organ  of  the  circulation  consists  of  muscu- 
lar fibres,  which  are  so  arranged  that  they  give  it  a coni- 
cal form,  and  compose  four  distinct  cavities  within  it. 

Two  of  these  cavities,  which  are  called  Auricles,  re- 
ceive the  contents  of  the  veins;  the  other  two  communi- 
cate with  the  arteries,  and  are  called  Ventricles. 

The  auricles  form  the  basis  of  the  cone;  the  ventricles 
the  body  and  apex. 

The  structure  of  the  auricles  is  much  less  firm  than 
that  of  the  ventricles,  and  consists  of  a smaller  proportion 
of  muscular  fibres.  They  appear  like  appendages  of  the 
heart,  while  the  ventricles  compose  the  body  of  the  vis- 
cus. 

The  ventricles  are  very  thick,  and  are  composed  of 
muscular  fibres  closely  compacted. 

The  figure  of  the  heart  is  not  regularly  conical;  for 

* The  pericardium  has  been  so  distended,  by  effusion  in  dropsy, 
that  it  has  formed  a tumour,  protruding  on  the  neck  from  under  the 
sternum.  This  tumour  had  a strong  pulsating  motion.  It  disappear- 
ed completely  when  the  other  hydropic  symptoms  were  relieved. 


51 


Connexions  of  the  Heart. 

a portion  of  it,  extending  from  the  apex  to  the  base,  is 
flattened;  and  in  its  natural  position,  this  flat  part  of  the 
surface  is  downwards. 

It  is  placed  obliquely  in  the  body;  so  that  its  base  pre- 
sents backward  and  to  the  right,  and  its  apex  forward 
and  to  the  left. 

Notwithstanding  this  obliquity,  the  terms  right  and  left 
are  applied  to  the  different  sides  of  the  heart,  and  to  the 
different  auricles  and  ventricles;  although  they  might, 
with  equal  propriety,  be  called  anterior  and  posterior. 

The  two  great  veins,  called  Vena  Cava,  which  bring 
the  blood  from  every  part  of  the  body,  open  into  the 
right  auricle  from  above  and  below;  the  right  auricle 
opens  into  the  right  ventricle;  and  from  this  ventricle 
arises  the  artery  denominated  Pulmonary , which  passes 
to  the  lungs. 

The  Pulmonary  veins,  which  bring  back  the  blood 
from  the  lungs,  open  into  the  left  auricle:  this  auricle 
opens  into  the  left  ventricle;  and  from  this  ventricle  pro- 
ceeds the  Aorta,  or  great  artery,  which  carries  blood  to 
every  part  of  the  body. 

The  heart  is  preserved  in  its  position,  1st,  by  the  venae 
cavae,  which  are  connected  to  all  the  parts  to  which  they 
are  contiguous  in  their  course;  2d,  by  the  vessels  which 
pass  between  it  and  the  lungs,  which  are  retained  in  a 
particular  position  by  the  mediastinum;  3d,  by  the  aorta, 
which  is  attached  to  the  mediastinum  in  its  course  down- 
wards, after  making  its  great  curve;  and  4th,  by  the  pe- 
ricardium, which  is  attached  to  the  great  vessels  and  to 
the  mediastinum.  By  these  different  modes  the  basis  of 
the  heart  is  fixed,  while  its  body  and  apex  are  perfectly 
free  from  attachment,  and  only  contiguous  to  the  peri- 
cardium. 

The  external  surface  of  the  heart,  being  formed  by  the 
pericardium,  is  very  smooth:  under  this  surface  a large 
quantity  ol  fat  is  often  found. 


52 


Right  Auricle . 

The  two  auricles  are  contiguous  to  each  other  at  the 
base,  and  are  separated  by  a partition  which  is  common 
to  both. 

The  Right  Auricle  originates  from  the  junction  of  the 
two  ven®  cav®.  These  veins  are  united  at  some  distance 
behind  the  right  ventricle,*  and  are  dilated  anteriorly  into 
a sac  or  pouch,  which  is  called  the  Sinus,  and  extends  to 
the  right  ventricle,  to  which  it  is  united. 

The  upper  part  of  this  pouch,  or  sinus,  forms  a point 
tvith  indented  edges,  which  is  detached  from  the  ventri- 
cle, and  lies  loose  on  the  right  side  of  the  aorta.  This 
point  has  some  resemblance  to  the  ear  of  a dog,  from 
from  which  circumstance  the  whole  cavity  has  been  called 
auricle ; but  by  many  persons  the  cavity  is  considered  as 
consisting  of  two  portions:  the  Auricle , strictly  speaking; 
and  the  Sinus  Venosus , above  described:  they  however 
form  but  one  cavity. 

This  portion  of  the  heart,  or  Right  Auricle , is  of  an 
irregular  oblong  figure.  In  its  posterior  surface,  it  is 
indented;  for  the  direction  of  the  two  cav®,  at  their 
junction,  is  not  precisely  the  same;  but  they  form  an 
angle,  which  causes  this  indentation.  The  anterior  por- 
tion of  the  auricle,  or  that  which  appears  like  a pouch  be- 
tween the  ventricle  and  the  veins,  is  different  in  its  struc- 
ture from  the  posterior  part,  which  is  strictly  a portion  of 
the  veins.  It  consists  simply  of  muscular  fibres  which 
are  arranged  in  fasciculi  that  cover  the  whole  internal  sur- 
face: this  is  also  the  case  with  the  point,  or  that  part  which 
is  strictly  called  auricle. 

These  fasciculi  are  denominated  Musculi  Pectmati , 
from  their  resemblance  to  the  teeth  of  a comb. 

That  part  of  the  internal  surface,  which  is  formed  by 

* In  this  description  the  heart  is  supposed  to  be  in  its  natural  po- 
sition. 


Right  Ventricle.  53 

the  septum,  is  smooth;  and  the  whole  is  covered  by  a 
delicate  membrane. 

On  the  surface  of  the  septum,  below  the  middle,  is  an 
oval  depression,  which  has  a thick  edge  or  margin:  this 
is  called  the  Fossa  Ovalis.  In  the  foetal  heart,  it  was  the 
Foramen  Ovale,  or  aperture  which  forms  the  communi- 
cation between  the  two  auricles. 

Near  this  fossa  is  a large  semilunar  plait,  or  valve, 
with  its  points  and  concave  edge  uppermost,  and  convex 
edge  downwards.  It  wras  described  by  Eustachius,  and, 
therefore,  is  called  the  Valve  of  Eustachius. 

Anterior  to  this  valve,  and  near  the  union  of  the  auri- 
cle and  ventricle,  is  the  orifice  of  the  proper  vein  of  the 
heart,  or  the  coronary  vein.  This  orifice  is  covered  by 
another  semilunar  valve,  which  is  sometimes  reticulated. 

The  aperture,  which  forms  the  communication  between 
the  right  auricle  and  right  ventricle,  is  about  an  inch  in 
diameter.  From  its  whole  margin  arises  a valvular  ring, 
or  duplicature  of  the  membrane  lining  the  surface:  this 
circular  valve  is  divided  into  three  angular  portions, 
which  are  called  Valvulce  Tricuspides.  From  their  mar- 
gins proceed  a great  number  of  fine  tendinous  threads, 
which  are  connected  to  a number  of  distinct  portions  of 
muscular  substance,  which  arise  from  the  ventricle. 

The  right  Ventricle , when  examined  separate  from  the 
other  parts  of  the  heart,  is  rather  triangular  in  its  figure. 
It  is  composed  entirely  of  muscular  fibres  closely  com- 
pacted; and  is  much  thicker  than  the  auricle,  although 
not  so  thick  as  the  other  ventricle.  Its  internal  surface  is 
composed  of  bundles  or  columns  of  fleshy  fibres,  which 
are  of  various  thickness  and  length.  Some  of  these  co- 
lumns arise  from  the  ventricle,  and  are  connected  with 
the  tendinous  threads,  which  are  attached  to  the  margin 
of  the  tricuspid  valves:  the  direction  of  them  is  from  the 
apex  of  the  heart  towards  the  base.  Others  of  the  columns 
arise  from  one  part  of  the  surface  of  the  ventricle,  and 


54 


Right  Ventricle. 

are  inserted  into  another  part.  A third  species  are  attach- 
ed to  the  ventricle  throughout  their  whole  length,  form- 
ing ridges  or  eminences  on  it.  The  columns  of  the  two 
last  described  species  are  very  numerous.  They  present 
an  elegant  reticulated  surface  when  the  ventricle  is  laid 
open,  and  appear  also  to  occupy  a considerable  portion 
of  the  cavity  of  the  heart,  which  some  of  them  run  across 
in  every  direction  near  the  apex.  They  are  all  covered 
by  a membrane  continued  from  the  auricle  and  the  tri- 
cuspid valves;  but  this  membrane  appears  more  delicate 
and  transparent  in  the  ventricle  than  it  is  in  the  auricle. 

A portion  of  the  internal  surface  of  the  ventricle,  which 
is  to  the  left,  is  much  smoother  and  less  fasciculated  than 
the  rest:  it  leads  to  the  orifice  of  the  pulmonary  artery, 
which  arises  from  it  near  the  basis  of  the  ventricle.  This 
artery  is  very  conspicuous,  externally,  at  the  basis  of  the 
heart. 

It  is  very  evident,  upon  the  first  inspection  of  the  heart, 
that  the  valvulae  tricuspides  will  permit  the  blood  to  flow 
from  the  auricle  to  the  ventricle;  but  must  rise  and  close 
the  orifice,  and  thereby  prevent  its  passage  back  again, 
when  the  ventricle  contracts. 

The  use  of  the  tendinous  threads,  which  connect  the 
valves  to  the  fleshy  columns,  is  also  very  evident:  the 
valve  is  supported  by  this  connexion,  and  prevented  from 
yielding  to  the  pressure  and  opening  a passage  into  the 
auricle.  The  blood,  therefore,  upon  the  contraction  of 
the  ventricle,  is  necessarily  forced  into  the  pulmonary 
artery;  the  passage  to  which  is  now  perfectly  free.  Into 
this  artery  the  membrane  lining  the  ventricle  seems  con- 
tinued; but  immediately  within  the  orifice  of  the  artery 
it  is  formed  into  three  semicircular  folds,  each  of  which 
adheres  to  the  surface  of  the  artery  by  its  circumference, 
while  the  edge  constituting  its  diameter  is  loose.  In  the 
middle  of  this  loose  edge,  is  a small  firm  tubercle,  called 


55 


Left  Auricle. 

Corpusculum  Arantiif  which  adds  to  the  strength  of  the 
valve.  Each  of  these  valves,  by  its  connexion  with  the 
artery,  forms  a sac  or  pocket,  the  orifice  of  which  opens 
forward  towards  the  course  of  the  artery,  and  the  bottom 
of  it  presents  towards  the  ventricle.  Blood  will,  therefore, 
pass  from  the  ventricle  in  the  artery,  and  along  it,  with- 
out filling  these  sacs;  and  on  the  contrary,  in  this  course, 
will  compress  them  and  keep  them  empty.  If  it  moves 
in  the  artery  towards  the  heart,  it  will  necessarily  fill 
these  sacs,  and  press  the  semicircular  portions  from  the 
sides  of  the  artery  against  each  other:  by  this  means  a 
partition,  or  septum,  consisting  of  three  portions,  will  be 
formed  between  the  artery  and  the  heart,  which  will  al- 
ways exist  when  the  artery  compresses  (or  acts  upon) 
its  contents.  It  is  demonstrable,  by  injecting  wax  into 
the  artery,  in  a retrograde  direction,  that  these  valves  do 
not  form  aflat  septum,  but  one  which  is  convex  towards 
the  heart,  and  concave  towards  the  artery;  and  that  this 
convexity  is  composed  of  three  distinct  parts,  each  of 
which  is  convex.  At  the  place  where  these  valves  are 
fixed,  the  artery  bulges  out  when  distended  by  a retro- 
grade injection.  The  enlargements  thus  produced  are 
called  the  Sinuses  of  Valsalva , after  the  anatomist  who 
first  described  them.  The  valves  are  called  Semilunar ; 
and,  although  they  are  formed  by  a very  thin  membrane, 
they  are  very  strong. 

The  Left  Auricle  is  situated  on  the  left  side  of  the 
basis  of  the  heart.  It  originates  from  the  junction  of  the 
four  pulmonary  veins;  two  of  which  come  from  each 
side  of  the  thorax,  and  appear  to  form  a large  part  of  it. 
It  is  nearly  of  a cubic  form;  but  has  also  an  angular  por- 
tion, which  constitutes  the  proper  auricle,  that  proceeds 
from  the  upper  and  left  part  of  the  cavity,  and  is  situ- 
ated on  the  left  side  of  the  pulmonary  artery. 


* After  Arantius,  a professor  at  Bologna,  who  first  described  it. 


56 


Left  Ventricle. 

This  auricle  is  lined  by  a strong  membrane,  from 
which  the  valves  between  it  and  the  ventricle  originate: 
but  it  has  no  fleshy  columns  or  musculi  pectinati,  except 
in  the  angular  process  properly  called  auricle. 

These  valves,  and  the  orifice  communicating  with  the 
ventricle,  resemble  those  which  have  been  already  de- 
scribed between  the  right  auricle  and  ventricle;  but  with 
this  difference,  that  the  valvular  ring  is  divided  into  two 
portions  only,  instead  of  three,  which  are  called  Valvules 
Mitrales.  The  tendinous  threads,  which  are  connected  to 
the  muscular  columns,  are  also  attached  to  these  valves, 
as  in  the  case  of  the  right  auricle. 

These  valves  admit  the  passage  of  blood  from  the  au- 
ricle into  the  ventricle,  but  completely  prevent  its  return 
when  the  ventricle  contracts.  One  of  them  is  so  situated 
that  it  covers  the  mouth  of  the  aorta  while  the  blood  is 
flowing  into  the  ventricle,  and  leaves  that  orifice  open 
when  the  ventricle  contracts,  and  the  passage  to  the  au- 
ricle is  closed. 

The  Left  Ventricle  is  situated  posteriorly,  and  to  the 
left  of  the  Right  Ventricle:  its  figure  is  different,  for  it  is 
rather  conical,  and  it  is  also  longer. 

The  internal  surface  of  this  ventricle  resembles  that  of 
the  right  ventricle;  but  the  columnae  carneae  are  stronger 
and  larger. 

On  the  right  side  of  this  ventricle  is  the  mouth  of  the 
aorta.  The  surface  of  the  ventricle  near  this  opening  is 
smooth. 

The  cavity  of  this  ventricle  is  supposed  to  be  smaller 
than  that  of  the  right:  but  the  amount  of  the  difference  has 
not  been  accurately  ascertained. 

This  ventricle  must  have  much  more  force  than  the 
right,  as  its  parietes  are  so  much  thicker.  Their  thickness 
often  exceeds  half  an  inch. 

The  difference  in  the  strength  of  the  two  ventricles 
probably  corresponds  with  the  difference  between  the  ex- 
tent of  the  pulmonary  artery  and  the  aorta. 


57 


Muscular  Fibres  of  the  Heart. 

The  thickness  of  the  septum  between  the  ventricles 
is  thicker  than  the  sides  or  parietes  of  the  right  ventricle, 
and  less  thick  than  those  of  the  left. 

The  muscular  fibres  of  the  heart  are  generally  less 
florid  than  those  of  the  voluntary  muscles:  they  are  also 
more  closely  compacted  together.  The  direction  of  many 
of  them  is  oblique  or  spiral;  but  this  general  arrangement 
is  very  intricate:  it  is  such,  however,  that  the  cavities  of 
the  heart  are  lessened,  and  probably  completely  obliterat- 
ed, by  the  contraction  of  these  fibres.* 

The  external  surface  of  the  heart  is  covered  by  that 
portion  of  the  pericardium  which  adheres  to  it.  Adipose 
matter  is  often  deposited  between  this  membrane  and  the 
muscular  surface;  being  distributed  irregularly  in  various 
places. 

This  membrane  is  continued  from  the  surface  of  the 
ventricles  over  that  of  the  auricles.  When  it  is  dissected 
off"  from  the  place  of  their  junction,  these  surfaces  appear 
very  distinct  from  each  other. 

The  proper  bloodvessels  of  the  heart  appear  to  be  ar- 
ranged in  conformity  to  the  general  laws  of  the  circula- 
tion, and  are  very  conspicuous  on  the  surface.  There  are 
two  arteries  which  arise  from  the  aorta  immediately  after 
it  leaves  the  heart,  so  that  their  orifices  are  covered  by  two 
of  the  semilunar  valves.  One  of  these  passes  from  the 
aorta  between  the  pulmonary  artery  and  the  right  auricle, 
and  continues  in  a circular  course  in  the  groove  between 
the  right  auricle  and  the  right  ventricle,  and  sends  off  its 
principal  branches  to  the  right  side  of  the  heart. 

The  other  artery  of  the  heart  passes  between  the  pul- 
monary artery  and  the  left  auricle.  It  divides  into  two 
branches:  one,  which  is  anterior,  passes  to  a groove  on 
the  surface,  corresponding  to  the  septum  between  the  two 

* Mr.  Home  has  given  a precise  description  of  the  ipuscular  fibres 
of  the  heart  in  his  Croonian  Lecture.  London  Philosophical  Transac*- 
tions  for  1795, part  l.page  215. 

Vol.  II.  H 


58 


Coronary  Vessels,  &c. 

ventricles,  and  continues  on  it  to  the  apex  of  the  heart, 
sending  off  branches  in  its  course;  another,  which  is  pos- 
terior and  circumflex,  passes  between  the  left  auricle  and 
ventricle. 

The  great  vein  of  the  heart  opens  into  the  under  side  of 
the  right  auricle,  as  has  been  already  mentioned:  the  main 
trunk  of  this  vein  passes  for  some  distance  between  the 
left  auricle  and  ventricle.* 

From  the  course  of  these  different  vessels  round  the 
basis  of  the  ventricles  of  the  heart,  they  are  generally 
called  Coronary  Vessels:  the  arteries  are  denominated, 
from  their  position,  Right  and  Left  Coronary. 

The  nerves  of  the  heart  come  from  the  cardiac  plexus, 
which  is  composed  of  threads  derived  from  the  intercostal 
or  great  sympathetic  nerves,  and  the  nerves  of  the  eighth 
pair. 

* It  was  asserted  by  Vieussens  at  an  early  period,  in  the  last  centu- 
ry, and  soon  afterwards  by  Thebesius,  a German  Professor,  that  there 
were  a number  of  small  orifices  in  the  texture  of  the  heart,  which 
opened  into  the  different  cavities  on  both  sides  of  it. 

This  assertion  of  a fact  so  difficult  to  reconcile  with  the  general 
principles  of  the  circulation,  was  received  with  great  hesitation:  and 
although  it  was  confirmed  by  some  very  respectable  anatomists  of  the 
last  century,  it  was  denied  by  others.  Some  of  the  anatomists  of  the 
present  day  have  denied  the  existence  of  these  orifices,  and  some 
others  have  neglected  them  entirely. 

The  subject  has  lately  been  brought  forward  in  the  London  Philo- 
sophical Transactions  for  1798,  Part  I,  by  a very  respectable  anato- 
mist, Mr.  Abernethy,  who  states  that  he  has  often  passed  a coarse 
waxen  injection  from  the  proper  arteries  and  veins  of  the  heart  into 
all  the  cavities  of  that  organ,  and  particularly  into  the  Left  Ventricle. 
But  it  was  only  in  subjects  with  diseased  lungs  that  this  was  practica- 
ble. 

The  existence  of  this  communication  between  the  coronary  vessels 
and  the  great  cavities  of  the  heart  seems  therefore  to  be  proved.  The 
easy  demonstration  in  such  subjects  is  ingeniously  referred  by  Mr. 
Abernethy,  to  the  obstruction  of  the  circulation  in  the  lungs:  and  he 
regards  the  communication  as  a provision  enabling  the  coronary  ves- 
sels to  unload  themselves,  when  the  coronary  vein  c«nnot  discharge 
freely  into  the  right  auricle. 


The  Great  Vessels . 


59 


SECTION  III. 

Of  the  Aorta , the  Pulmonary  Artery  and  V eins , and  the 
Vena  Cava;  at  their  commencement . 

THE  two  great  arteries,  which  arise  from  the  heart, 
commence  abruptly,  and  appear  to  be  extremely  different 
in  their  composition  and  structure  from  the  heart. 

They  are  composed  of  a substance,  which  has  a whitish 
colour  and  very  dense  texture,  and  is  very  elastic  as  well  as 
firm  and  strong. 

When  the  pericardium  is  removed,  these  arteries  ap- 
pear to  proceed  together  from  the  upper  part  of  the  basis 
of  the  heart:  the  pulmonary  artery  being  placed  to  the  left 
of  the  aorta  with  the  left  auricle  on  the  left  side  of  it,  and 
the  right  auricle  on  the  right  side  of  the  aorta.  The  pul- 
monary artery  arises  from  the  most  anterior,  and  left  part 
of  the  basis  of  the  right  ventricle,  and  proceeds  obliquely 
backwards  and  upwards;  inclining  gradually  to  the  left 
side  for  about  eighteen  or  twenty  lines;  when  it  divides 
into  two  branches  which  pass  to  the  two  lungs. 

The  aorta  arises  from  the  left  ventricle,  under  the  origin 
of  the  pulmonary  artery,  and  immediately  proceeds  to  the 
right,  covered  by  that  vessel,  until  it  mounts  up  between 
it  and  the  right  auricle:  it  then  forms  a great  curve,  or 
arch,  which  turns  backward  and  to  the  left,  to  a considera- 
ble distance  beyond  the  pulmonary  artery.  In  this  course, 
it  crosses  the  right  branch  of  the  pulmonary  artery;  and, 
turning  down  in  the  angle  between  it  and  the  left  branch, 
takes  a position  on  the  left  side  of  the  spine. 

The  course  of  this  artery,  from  its  commencement  at 
the  ventricle,  to  the  end  of  the  great  curve  or  arch,  is  ex- 
tremely varied. 

The  uppermost  part  of  the  curve- is  in  the  bottom  of 
the  chamber  formed  by  the  separation  of  the  laminae  of 
the  mediastinum  when  they  join  the  first  rib  on  each  side. 


60  Pulmonary  Artery  and  Veins  and  Vena  Caves. 

From  this  part  of  the  curve  three  large  branches  go 
off,  viz:  one,  which  soon  divides  into  the  carotid  and  the 
subclavian  arteries  of  the  right  side;  a second,  somewhat 
smaller,  which  is  the  left  carotid;  and  a third,  which  is  the 
left  subclavian  artery. 

When  the  heart  and  its  great  vessels  are  viewed  from 
behind,  (after  they  have  all  been  filled  with  injection;  and 
the  pericardium,  mediastinum,  and  windpipe  have  been 
removed,)  the  aorta  appears  first,  descending  behind  the 
other  vessels;  the  pulmonary  artery  then  appears,  dividing 
so  as  to  form  an  obtuse  angle  with  its  two  great  branches, 
each  of  which  divides  again  before  it  enters  the  lung  to 
which  it  is  destined. 

Under  the  main  trunk  of  the  pulmonary  artery  is  the 
left  auricle:  its  posterior  surface  is  nearly  of  a square  form, 
and  each  of  the  pulmonary  veins  proceeds  from  one  of  its 
angles.  These  veins  ramify  in  the  substance  of  the  lungs, 
at  a very  short  distance  from  the  auricle:  the  two  upper- 
most of  them  are  situated  rather  anterior  to  the  branches 
of  the  pulmonary  artery. 

In  this  posterior  view,  the  pulmonary  vessels  of  the 
right  side  cover  a great  part  of  the  right  auricle,  as  it  is 
anterior  to  them.  The  lower  portion  of  the  auricle,  with 
the  termination  of  the  inferior  cava,  is  to  be  seen  below 
them.  Above  them,  the  superior  cava  appears;  and  in 
that  part  of  it,  which  is  immediately  above  the  right 
branch  of  the  pulmonary  artery,  is  the  orifice  of  the  vena 
azygos. 

In  its  natural  situation  in  the  thorax,  the  superior  cava 
is  connected  by  cellular  membrane  to  the  right  lamina  of 
the  mediastinum,  and  supported  by  it.  At  a small  distance 
below  the  upper  edge  of  the  sternum,  it  receives  the  trunk 
formed  by  the  left  subclavian  and  internal  jugular  vein 
which  passes  obliquely  across  the  sternum  below  its  inner 
edge,  in  the  upper  space  between  the  laminae  of  the  medi- 
astinum. 


61 


' . & 


CHAPTER  III. 

OP  THE  TRACHEA  AND  THE  LUNGS. 

.Although  the  principal  part  of  the  windpipe  is 
situated  in  the  neck  above  the  cavity  of  the  thorax,  it  is 
so  intimately  connected  with  the  lungs,  that  it. is  necessary 
to  describe  them  together. 


SECTION  I. 

Of  the  Trachea . 

Trachea  is  the  technical  name  for  the  windpipe,  or 
tube  which  passes  from  the  larynx  to  the  lungs. 

This  tube  begins  at  the  lower  edge  of  the  cricoid  car- 
tilage, and  passes  down  the  neck  in  front  of  the  cesopha-' 
gus  as  low  as  the  third  dorsal  vertebra,  when  it  divides 
into  two  branches  called  Bronchia , one  of  which  goes  to 
the  right  and  the  other  to  the  left  lung  and  ramifies  very 
minutely  in  them. 

There  is  in  its  structure  a number  of  flat  cartilaginous 
rings  placed  at  small  distances  from  each  other,  the  edges 
of  which  are  connected  by  membrane  so  that  they  com- 
pose a tube. 

These  cartilaginous  rings  are  not  complete,  for  they  do 
not  form  more  than  three  fourths  or  four  fifths  of  a circle; 
but  their  ends  are  connected  by  a membrane  which  forms 
the  posterior  part  of  the  tube. 

They  are  not  alike  in  their  size  or  form;  some  of  them 
are  rendered  broader  than  others,  by  the  union  of  two  or 
three  rings  with  each  other,  as  the  uppermost.  The  lower- 
most also  is  broad,  and  has  a form  which  is  accommodated 


62 


Structure  of  the  Trachea. 

to  the  bifurcation  of  the  tube.  Their  number  varies,  in 
different  persons,  from  fifteen  to  twenty. 

These  rings  may  be  considered  as  forming  a part  of  the 
first  proper  coat  of  the  trachea;  which  is  composed  of 
them,  and  of  an  elastic  membrane  that  occupies  all  the 
interstice  between  them;  so  that  the  cartilages  may  be  re- 
garded as  fixed  in  this  membrane. 

A similar  arrangement  of  rings  exists  in  the  great 
branches  of  the  bronchiae;  but  after  they  ramify  in  the 
lungs,  the  cartilages  are  no  longer  in  the  form  of  rings: 
they  are  irregular  in  their  figures,  and  are  so  arranged  in 
the  membrane  that  they  keep  the  tube  completely  open. 
These  portions  of  cartilage  do  not  continue  throughout 
the  whole  extent  of  the  ramifications;  for  they  become 
smaller,  and  finally  disappear,  while  the  membranous  tube 
continues  without  them,  ramifying  minutely,  and  proba- 
bly forming  the  air  cells  of  the  lungs. 

This  membrane  is  very  elastic:  the  lungs  are  very  elastic 
also;  and  it  is  probable  that  their  elasticity  is  derived  from 
this  membrane. 

On  the  inside  of  this  coat  of  the  trachea  is  an  arrange- 
ment of  muscular  fibres,  which  may  be  called  a muscular 
coat.  It  is  best  seen  by  peeling  off  or  removing  the  inter- 
nal coat  to  be  next  described. 

On  the  membranous  part  of  the  trachea,  where  the  car- 
tilaginous rings  are  deficient,  these  muscular  fibres  run 
evidently  in  a transverse  direction:  in  the  spaces  between 
the  cartilages  their  direction  is  longitudinal.  There  is 
some  reason  to  doubt  whether  these  longitudinal  fibres  are 
confined  altogether  to  the  spaces  between  the  cartilaginous 
rings,  and  attached  only  to  their  edges,  because  there  is  a 
fleshy  substance  on  the  internal  surface  of  the  rings,  which 
appears  to  be  continued  from  the  spaces  between  them. 

The  internal  coat  of  the  trachea  is  a thin  and  delicate 
membrane,  perforated  with  an  immense  number  of  small 
foramina,  which  are  the  oriiices  of  mucous  ducts. 


63 


Black  Glands  of  the  Bronchia  - 

On  the  surface  of  this  membrane  there  is  an  appearance 
of  longitudinal  fibres  which  are  not  distributed  uniformly 
over  it,  but  run  in  fasciculi  in  some  places,  and  appear  to 
be  deficient  in  others. ' These  fasciculi  are  particularly 
conspicuous  in  the  ramifications  of  the  bronchia  in  the 
lungs. 

On  the  posterior  membranous  portion  of  the  trachea, 
where  the  cartilages  are  deficient,  a considerable  number 
of  small  glandular  bodies  are  placed,  which  are  supposed 
to  communicate  with  the  mucous  ducts  that  open  on  the 
internal  surface.  If  these  bodies  are  removed  from  the 
external  surface  of  this  portion,  and  the  muscular  fibres 
are  also  removed  from  the  internal,  a very  thin  membrane 
only  remains,  which  is  very  different  from  that  which  is 
left  between  the  rings,  when  the  fleshy  substance  is  re- 
moved from  that  situation. 

The  reason  of  the  deficiency  in  the  rings,  at  this  poste- 
rior part*  is  not  very  obvious.  It  continues  in  the  bronchias 
until  the  form  of  their  cartilages  is  changed  in  the  lungs: 
if  it  were  only  to  accommodate  the  oesophagus,  during  the 
passage  of  food,  there  would  be  no  occasion  for  its  exten- 
sion to  the  bronchiae. 

At  the  bifurcation  of  the  trachea,  and  on  the  bronchiae, 
are  a number  of  black  coloured  bodies,  which  resemble 
the  lymphatic  glands  in  form  and  texture.  They  continue 
on  the  ramifications  of  the  bronchiae  some  distance  into 
the  substance  of  the  lungs.  Their  number  is  often  very- 
considerable;  and  they  vary  in  size  from  three  or  four 
lines  in  diameter  to  eighteen  or  twenty.  As  lymphatic 
vessels  have  been  traced  to  and  from  them  during  their 
course  to  the  thoracic  duct,  they  are  considered  as  lvm 
phatic  glands. 


64 


Root  of  the  Lungs . 


SECTION  II. 

Of  the  Lungs. 

THERE  are  two  of  these  organs:  each  of  which  occu- 
pies one  of  the  great  cavities  of  the  thorax. 

When  placed  together,  in  their  natural  position,  they 
resemble  the  hoof  of  the  ox,  with  its  back  part  forward; 
but  they  are  at  such  a distance  from  each  other,  and  of 
such  a figure,  that  they  allow  the  mediastinum  and  heart 
to  intervene;  and  they  cover  every  part  of  the  heart  ante- 
riorly, except  a small  portion  at  the  apex. 

Each  lung  fills  completely  the  cavity  in  which  it  is 
placed,  and  every  part  of  its  external  surface  is  in  con- 
tact with  some  part  of  the  internal  surface  of  the  cavity; 
but  when  in  a natural  and  healthy  state,  it  is  not  con- 
nected with  any  part  except  the  laminae  of  .the  medias- 
tinum. One  great  branch  of  the  trachea  and  of  the  pul- 
monary artery  pass  from  the  mediastinum  to  each  lung, 
and  enter  it  at  a place  which  is  rather  nearer  to  the 
upper  rib  than  to  the  diaphragm,  and  much  nearer  to 
the  spine  than  the  sternum:  at  this  place  also  the  pulmo- 
nary veins  return  from  the  lung  to  the  heart. 

These  vessels  are  inclosed  in  a membrane,  which  is 
continued  over  them  from  the  mediastinum,  and  ex- 
tended from  them  to  the  lung.  Thus  covered,  they  con- 
stitute what  has  been  called  the  Root  of  the  Lung. 

When  their  covering,  derived  from  the  mediastinum, 
is  removed,  the  situation  of  these  vessels  appears  to  be 
such  that  the  bronchias  are  posterior,  the  branches  of  the 
pulmonary  artery  are  rather  above  and  before,  and  the 
veins  below  and  before  them. 

Each  of  these  vessels  ramifies  before  it  enters  into  the 
substance  of  the  lungs:  the  bronchiae  and  the  branches  of 
the  pulmonary  artery  send  each  a large  branch  downward 


65 


Colour  of  the  Lungs. 

to  the  inferior  part  of  the  lungs,  from  which  the  lower 
pulmonary  veins  pass  in  a direction  nearly  horizontal.  In 
general,  each  of  the  smaller  ramifications  of  the  bronchize 
in  the  lungs  is  attended  by  an  artery  and  a vein. 

Each  lung  is  divided,  by  very  deep  fissures,  into  por- 
tions which  are  called  Lobes.  The  right  lung  is  composed 
of  three  of  these  lobes,  and  the  left  lung  of  two. 

The  lungs  are  covered,  as  has  been  already  stated, 
with  the  reflected  portion  of  the  pleura  continued  from 
the  mediastinum,  which  is  very  delicate,  and  almost 
transparent.  They  have,  therefore,  a very  smooth  sur- 
face, which  is  kept  moist  by  exudation  from  the  arteries 
of  the  membrane. 

The  Colour  of  the  Lungs  is  different  in  different  sub- 
jects. In  children  they  are  of  a light  red  colour;  in  adults 
they  are  often  of  a light  grey;  owing  to  the  deposition  of 
a black  pigment  in  the  substance  immediately  under  the 
membranes  which  form  their  external  surface.  Their 
eolour  is  often  formed  by  a mixture  of  red  and  black.  In 
this  case  they  are  more  loaded  with  blood,  and  the  ves- 
sels of  the  internal  membranes  being  distended  with  it, 
the  red  colour  is  derived  from  them. 

The  black  pigment  sometimes  appears  in  round  spots 
of  three  or  four  lines  in  diameter:  under  the  external 
membrane  it  is  often  in  much  smaller  portions,  and 
sometimes  is  arranged  in  lines  in  the  interstices  of  the 
lobuli,  to  be  hereafter  mentioned.  It  is  also  diffused  in 
small  quantities  throughout  the  substance  of  the  lungs. 

The  source  of  this  substance,  and  the  use  of  it,  are 
unknown. 

The  lungs  are  of  a soft  spongy  texture;  and,  in  ani- 
mals that  have  breathed,  they  have  always  a considera- 
ble quantity  of  air  in  them. 

They  consist  of  cells,  which  communicate  with  the 
branches  of  the  trachea  that  ramify  through  them  in 
ever}"  part.  These  cells  are  extremely  small,  and  tli£ 

VOL.  II.  I 


66 


Structure  of  the  Lungs * 


membranes  which  compose  them  are  so  thin  and  deli- 
cate  that  if  they  are  all  filled  by  an  injection  of  wax, 
thrown  into  the  trachea,  the  whole  cellular  part  of  the 
lung  will  appear  like  a mass  of  wax.  If  a corroded  pre- 
paration be  made  of  a lung  injected  in  this  manner  with 
force,  the  wax  will  appear  like  a concretion. 

These  effects  of  injection  prove  that  the  membranes 
of  which  the  cells  are  formed  are  very  thin;  and,  of 
course,  that  their  volume  is  very  small  when  compared 
with  the  capacity  of  the  cells. 

In  those  corroded  preparations,  in  which  the  ramifica- 
tions of  the  bronchiae  are  detached  from  the  wax  of  the 
cells,  these  ramifications  become  extremely  small  indeed. 

If  the  lungs  of  the  human  subject,  or  of  animals  of 
similar  construction,  be  examined  when  they  are  inflated, 
their  cellular  structure  will  be  very  obvious,  although, 
their  cells  are  so  small  that  they  cannot  commonly  be 
distinguished  by  the  naked  eye.  F.ach  of  the  extreme  ra- 
mifications of  the  bronchiae  appears  to  be  surrounded  by 
a portion  of  this  cellular  substance,  which  is  gradually 
distended  when  air  is  blown  into  the  ramification. 

This  cellular  substance  is  formed  into  small  portions 
of  various  angular  figures,  which  are  denominated  Lo~ 
bull:  these  can  be  separated  to  a considerable  extent 
from  each  other.  They  are  covered  by  the  proper  coat 
of  the  lungs,  which  is  extremely  delicate,  and  closely 
connected  to  the  general  covering  derived  from  the 
pleura.  Between  the  lobuli,  when  they  are  in  contact 
with  each  other,  there  is  a portion  of  common  cellular 
substance,  which  is  easily  distinguished  through  the 
membrane  covering  the  lungs.  This  is  very  distinct 
from  the  cellular  structure  which  communicates  with 
the  ramifications  of  the  bronchiae,  and  contains  air;  for  it 
has  no  communication  with  the  air,  unless  the  proper 
coat  of  the  lungs  be  ruptured.  If  a pipe  be  introduced 
by  a puncture  of  the  external  coat  of  the  lungs,  and  this 


67 


The  Thorax  of  the  Fcetas. 

interstitial  cellular  membrane  be  inflated,  it  will  com- 
press the  lobuli.  This  cellular  membrane  is  alwa)Ts  free 
from  adipose  matter:  it  may  be  easily  examined  in  the 
lungs  of  the  bullock. 

Upon  the  membranes  which  compose  the  air  cells,  the 
pulmonary  artery  and  vein  ramify  most  minutely;  and  it 
seems  to  have  been  proved  within  the  last  thirty  years, 
by  the  united  labours  of  chemists  and  physiologists,  that 
the  great  object  of  respiration  is  to  effect  a chemical  pro- 
cess between  the  atmospheric  air,  when  taken  into  the 
air  cells,  and  the  blood  which  circulates  in  these  vessels. 

In  addition  to  the  bloodvessels  which  thus  pass  through 
the  substance  of  the  lungs,  there  are  several  smaller  ar- 
teries, denominated  Bronchial,  which  arise  either  from 
the  upper  intercostal,  or  from  the  aorta  itself:  they  pass 
upon  the  bronchiae,  and  are  distributed  to  the  substance 
of  the  lungs.  The  veins  which  correspond  with  these  ar- 
teries terminate  ultimately  in  the  vena  azygos. 

The  nerves  of  the  lungs  are  small  in  proportion  to  the 
bulk  of  these  organs.  They  are  derived  principally  from 
the  par  vagum  and  the  intercostal  nerves. 

The  elasticity  of  the  air  cells  -of  the  lungs  and  of  the 
ramifications  of  the  bronchia^  which  lead  to  them,  ap- 
pears by  their  rapid  contraction  after  distention,  and  by 
the  force  with  which  they  expel  the  air  which  is  used  to 
inflate  them  when  taken  out  of  the  thorax. 

The  Thorax  of  the  Foetus. 

In  the  cavity  between  the  lamin®  of  the  mediastinum, 
where  they  approach  each  other  from  the  first  ribs,  is  situ- 
ated a substance  which  is  denominated  the 

Thymus  Gland. 

This  substance  gradually  diminishes  after  birth,  so  that 
in  the  adult  it  is  often  not  to  be  found:  and  when  it  exists 
it  is  changed  in  its  texture,  being  much  firmer,  as  well  as 
greatly  diminished. 


63 


The  Thorax  of  the  Foetus. 

In  the  foetus  it  is  of  a pale  red  colour;  and  during  in- 
fancy it  has  a yellowish  tinge.  It  generally  extends  from 
the  thyroid  gland,  or  a little  below  it,  to  the  pericardium. 
From  its  superior  portion  two  lateral  processes  are  ex- 
tended upwards:  below,  it  is  formed  into  two  lobes,  which 
lie  on  the  pericardium. 

If  an  incision  be  made  into  its  substance,  a fluid  can  be 
pressed  out,  which  has  a whitish  colour,  and  coagulates 
upon  the  addition  of  alcohol. 

Although  it  is  called  a gland,  no  excretory  duct  has 
ever  been  found  connected  with  it. 

The  bloodvessels  of  this  body  are  derived  from  the 
thyroid  branches  of  the  subclavians,  from  the  internal 
mammaries,  and  the  vessels  of  the  pericardium  and  medi- 
astinum. 

The  Heart , 

And  the  great  arteries  which  proceed  from  it,  have 
some  very  interesting  peculiarities  in  the  foetus. 

In  the  septum  between  the  two  auricles,  is  a foramen 
of  sufficient  size  to  permit  the  passage  of  a large  quill, 
which  inclines  to  the  oval  form,  with  its  longest  diameter 
vertical  when  the  body  is  erect.  On  the  left  side  of  the 
septum,  a valve,  formed  by  the  lining  membranes,  is  con- 
nected to  this  foramen;  and  allows  a free  passage  to  a fluid 
moving  from  the  right  auricle  to  the  left,  but  prevents  the 
passage  of  a fluid  from  the  left  to  the  right.  This  structure 
is  evidently  calculated  to  allow  some  of  the  blood  which 
flows  into  the  right  auricle  from  the  two  venae  cavae  to 
pass  into  the  left  auricle  of  the  heart,  instead  of  going  in- 
to the  right  ventricle.  As  the  contents  of  the  left  auricle 
pass  into  the  left  ventricle,  and  from  thence  into  the  aorta, 
it  is  obvious  that  the  blood,  which  passes  from  the  right 
auricle  into  the  left  through  this  foramen,  must  be  trans- 
mitted from  the  system  of  the  vena  cava  to  the  system  of 
the  aorta  without  going  through  the  lungs,  as  it  must  ne- 


The  Thorax  of  the  Foetus.  69 

tessarily  do  in  subjects  who  do  not  enjoy  the  foetal  struc- 
ture. 

The  Pulmonary  Artery  and  the  Aorta 

Have  a communication  in  the  foetus,  which  is  very  ana- 
logous to  the  communication  between  the  auricles  of  the 
heart. 

From  the  pulmonary  artery,  where  it  divides  into  the 
two  great  branches,  another  large  branch  continues,  in  the 
direction  of  the  main  trunk,  until  it  joins  the  aorta;  with 
which  it  communicates  at  a small  distance  below  the  ori- 
gin of  the  left  subclavian  artery.  In  the  young  subject  that 
has  never  respired,  it  appears  as  if  the  pulmonary  artery 
was  continued  into  the  aorta,  and  sent  off’  in  its  course,  a 
branch  on  each  side,  much  smaller  than  itself,  to  each  lung. 
In  subjects  that  have  lived  a few  days,  these  branches  to 
the  lungs  are  much  larger;  and  then  the  main  pulmonary 
artery  appears  to  have  divided  into  three  branches:  one  to 
each  lung,  and  one  to  the  aorta;  but  that  which  continues 
to  the  aorta  is  larger  than  either  of  the  others. 

In  the  course  of  time,  however,  this  branch  of  the  aorta 
is  contracted,  so  that  no  fluid  passes  through  it;  and  it  has 
the  appearance  of  a ligament,  in  which  state  it  remains. 

The  course  of  the  blood  from  the  right  ventricle, 
through  the  pulmonary  artery,  to  the  aorta  below  its  curve, 
is  more  direct  than  that  from  the  left  ventricle  to  the  same 
spot,  through  the  aorta  at  its  commencement.  The  column 
of  blood  in  the  aorta  below  its  curve  is  evidently  propel- 
led by  the  force  of  both  ventricles:  and  this  circumstance, 
although  it  seems  to  proceed  merely  from  the  state  of  the 
foetal  lungs,  is  particularly  calculated  for  the  very  exten- 
sive circulation  which  the  foetus  carries  on,  by  means  of 
the  umbilical  arteries  and  vein  in  the  placenta. 


70 


General  Observations. 


The  Lungs  of  the  Foetus 

Differ  greatly  from  those  of  the  adult.  They  appear 
solid,  as  if  they  were  composed  of  the  parenchymatous 
substance  which  constitutes  the  matter  of  glands,  rather 
than  the  light  spongy  substance  of  the  lungs  of  adults. 
They  differ  also  in  colour  from  the  lungs  of  older  subjects, 
being  of  a dull  red. 

They  have  greater  specific  gravity  than  water;  but  if 
air  be  once  inspired,  so  much  of  it  remains  in  them  that 
they  ever  afterwards  float  in  that  fluid. 

The  nature  of  the  process  of  respiration,  and  its  effects 
upon  the  animal  economy,  particularly  upon  the  action 
of  the  heart,  appear  to  be  much  better  understood  at 
this  time  than  they  were  before  the  discovery  of  the 
composition  of  the  atmosphere,  by  Dr.  Priestley  and 
by  Mr.  Scheele.  The  publications  upon  this  subject, 
which  have  appeared  since  that  period,  viz.  1774,  are 
therefore  much  more  interesting  to  the  student  of  me* 
dicine  than  those  which  preceded  them.  Two  of  these 
publications  ought  to  be  particularly  noticed  by  him: 
viz.  an  essay,  by  Dr.  Edward  Goodwyn,  intitled  “The 
Connexion  of  life  with  respiration;”  and — the  “ Phy- 
- siological  Researches  of  M.  Bichat  upon  Life  and  Death. 
Part  Second.”* 

The  general  doctrines  respecting  the  oxygenation  or  de- 
carbonation  ©f  the  blood,  and  the  absolute  necessity 
that  it  should  take  place  to  a certain  degree  in  order 

* The  student  will  derive  much  information  respecting  the  pub- 
lications on  this  subject,  prior  to  1804,  from  Dr.  Bostock’s  Essay  on 
Respiration. — Since  the  publication  of  that  essay  several  interesting 
papers  on  respiration  have  appeared,  viz:  Two  memoirs  by  the  late 
Abbe  Spalanzani; — “ An  Inquiry  into  the  Changes  induced  on  At- 
mospheric Air  by  the  Germination  of  Seeds,  &c.”  by  Ellis; — two  very 
important  communications  by  Messrs.  Allen  and  Pepys  in  the  Trans- 
actions of  the  Royal  Society  of  London  for  1808  and  1809; — and 
“ Further  Inquiries  into  the  changes  induced  on  Atmospheric  Air.” 
Also  by  Ellis. 


71 


Cases  of  Malformation. 

to  preserve  life,  are  confirmed  by  a number  of  cases 
of  malformation  of  the  heart  or  the  great  vessels,  in 
which  the  structure  was  such  that  a considerable  por- 
tion of  venous  blood  passed  from  the  right  side  of  the 
heart  to  the  aorta,  without  going  through  the  lungs. 
In  these  different  cases,  notwithstanding  the  structure 
was  somewhat  varied,  the  symptoms  produced  were 
very  much  alike;  differing  in  the  respective  patients  in 
degree  only,  and  not  in  kind. 

The  symptoms  indicating  this  structure  are  blue  colour 
of  the  face,  (such  as  generally  accompanies  suffocation) 
extending  more  or  less  over  the  whole  body,  and  par- 
ticularly apparent  under  the  nails  of  the  fingers  and 
toes;  anxiety  about  the  region  of  the  heart;  palpitation; 
laborious  respiration;  sensations  of  great  debility,  &c.: 
all  of  which  are  greatly  aggravated  by  muscular  exer- 
tion. These  effects  have  generally  appeared  to  be  pro- 
portioned to  the  quantity  of  venous  blood  admitted  into 
the  aortic  system.^ 

When  these  appearances  take  place  immediately 
after  birth,  it  is  probable  that  they  depend  entirely  upon 
malformation  of  the  heart  or  great  vessels;  but  when 
they  commence  at  a subsequent  period,  they  are  com- 
monly the  effect  of  a diseased  alteration  in  the  lungs. 
They  sometimes  occur  near  the  termination  of  fatal 
cases  of  pneumonia  or  catarrh;  but  a different  cause, 
which  has  not  latterly  been  suspected,  appears  to  have 
produced  them  in  the  following  case  related  by  Dr. 
Marcet,  in  the  first  volume  of  the  Edinburgh  Medical 
and  Physical  Journal. 

The  blue  colour  occurred  in  a young  woman  twenty- 
one  years  of  age,  in  whom  it  had  never  been  observed 

* Cases  of  this  kind  are  related  in  sereral  of  the  periodical  pub- 
lications on  medical  subjects.  Two  of  them  were  described  by  the 
late  Dr.  William  Hunter  in  the  sixth  volume  of  Medical  Observa- 
tions and  Inquiries,  by  a Society  of  Physicians  in  London;  one 
(quoted  by  Dr.  Goodwyn)  is  in  the  Observationes  Anatomicae  of 
Sandifort;  and  another,  by  Dr.  J.  S.  Dorsey,  has  lately  been  publish- 
ed in  the  first  number  of  the  New  England  Journal  of  Medicine  and 
Surgery. 


72  Adhesion  of  the  Lungs  to  the  Thorax. 

before.  It  came  on  during  an  affection  of  the  breast,  and 
was  attended  with  great  prostration  of  strength  and  dif- 
ficulty of  breathing;  as  well  as  cough,  cedema  of  the 
hands  and  feet,  and  several  other  symptoms.  About 
seven  weeks  after  the  commencement  of  these  symp- 
toms she  died;  when  it  was  ascertained  by  dissection, 
that  there  xuas  no  unnatural  communication  whatever 
between  the  cavities  of  the  heart , and  that  its  valves 
were  all  in  a perfect  and  natural  state.  The  lungs  were 
free  from  tubercles,  or  any  other  appearance  of  disease. 
Their  substance  seemed  more  compact  than  usual,  espe- 
cially the  left  lung,  although  it  did  not  sink  in  water; 
but  they  adhered  every  where  to  the  inner  surface  of  the 
thorax , to  the  diaphragm , and  to  the  pleura  covering  the 
pericardium. — This  case  is  the  more  remarkable,  be- 
cause numberless  instances  have  occurred  in  which 
very  large  portions  of  the  external  surface  of  the  lungs 
have  been  found  upon  dissection  to  adhere  to  the  inter- 
nal surface  of  the  thorax  without  the  occurrence  of 
such  symptoms  during  life. 


It  may  be  inferred,  from  a statement  published  by  M.  Du- 
puytren  in  a late  volume  of  the  Proceedings  of  the  Na- 
tional Institute  of  France,  that  the  oxygenation  or  de- 
carbonation  of  the  blood  is  much  affected,  in  respiration, 
by  an  influence  exercised  by  the  nerves  which  are  ap- 
propriated to  the  lungs.  From  his  account  it  appears, 
that  although  the  complete  division  of  the  eighth  pair 
of  nerves  produces  death  after  some  time;  yet,  in  the 
horse  whose  nerves  are  thus  divided,  life  continues, 
and  respiration  goes  on,  from  half  an  hour  to  ten  hours; 
but  his  arterial  blood  is  in  a state  of  great  disoxygena- 
tion  or  carbonation,  during  this  time. — This  fact  is  more 
remarkable,  because  venous  blood,  contained  in  a blad- 
der exposed  to  the  open  air,  will  become  oxygenated 
or  decarbonated. 

It  is  also  asserted  in  another  Memoir,  read  to  the  Na- 
tional Institute  by  Dr.  J.  M.  Proven$al,  that  animals  in 
whom  the  eighth  pair  of  nerves  has  been  divided,  do  not 


73 


Effects  of  Venous  Blood  on  the  Heart. 

consume  so  much  oxygen,  or  produce  so  much  carbonic 
acid,  by  a considerable  degree,  as  they  did  before  the 
division  of  these  nerves;  and  that  their  temperature  is 
considerably  reduced.* 


The  fact,  that  venous  blood  occasions  death  when  it  is  ad- 
mitted into  the  left  ventricle  of  the  heart,  and  the  aorta, 
is  truly  important.  Dr.  Goodwin  explained  it  by  sug- 
gesting that  this  blood  was  not  sufficiently  stimulating 
to  produce  the  necessary  excitement  of  the  heart;  but 
on  this  occasion  one  of  his  friends  proposed  to  him  the 
following  question:  Why  does  venous  blood  affect  the 
left  side  of  the  heart  in  this  injurious  manner,  when  it 
appears  to  exert  no  noxious  effects  whatever  on  the 
right  side  of  that  organ?  His  reply  may  be  seen  in  a 
note  at  the  82d  page  of  his  Essay,  in  the  first  edition. 
Bichat  has  offered  a solution  which  completely  re- 
solves this  difficulty,  viz.  “ The  effect  of  venous  blood 
upon  the  heart  is  produced  by  the  presence  of  this  blood 
in  the  proper,  or  coronary,  arteries  of  that  organ,  and 
not  in  its  great  cavities.”  For  the  animation  of  the  heart, 
like  that  of  the  other  parts  of  the  body,  depends  upon 
the  state  of  the  blood  in  the  arteries  which  penetrate  its 
texture. f And  while  the  heart  acts,  the  blood  of  the 
coronary  arteries  will  be  the  same  with  that  of  the  left 
ventricle.  See  Bichat’s  Researches,  P.  II.  art.  6,  § 2. 

The  French  Anatomists  appear  to  entertain  some  peculiar 
opinions  respecting  the  course  of  the  blood  in  the  foetus, 
which  have  a particular  relation  to  the  subject  last  men- 
tioned. Winslow,  who  paid  great  attention  to  the  valve 
of  Eustachius  in  the  right  auricle  of  the  heart,  was  of 
opinion,  that  this  valve  was  calculated  for  some  impor- 
tant purpose  in  the  foetal  economy.:}:  Although  his  hy- 

* These  Memoirs  are  republished  in  the  Eclectic  Repertory  of 
Philadelphia  for  April  and  October  1811. 

t It  is  probable  that  the  contents  of  the  great  cavities  of  the  heart 
have  no  more  effect  upon  its  animation  than  the  contents  of  the  sto- 
mach and  bowels  have  upon  the  animation  of  those  organs. 
fSee  Memoirs  of  the  Academy  of  Sciences  for  1717  and  1725, 

Vol.  II.  K 


74 


Sentiments  of  Sabatier , £sfc. 

pothesis  respecting  its  particular  use  has  not  been  re- 
tained by  his  countrymen,  many  of  them  have  adopted 
his  general  sentiment;  and  among  others  Sabatier.  That 
learned  anatomist  believed  that  this  valve,  in  the  foetal 
state,  serves  to  direct  the  blood  of  the  inferior  cava , after 
its  arrival  in  the  right  auricle , through  the  foramen  ovale 
into  the  left  auricle;  while  the  blood  of  the  upper  cava 
■passes  directly  into  the  right  ventricle.  His  opinion  seems 
to  be  supported  to  a certain  degree, 

1.  By  the  direction  in  which  the  two  columns  of  blood 
enter  the  auricle  from  the  two  venae  cavae. 

2.  By  the  position  of  the  Eustachian  valve. 

3.  By  the  foramen  ovale,  when  its  valve  is  complete; 
as  the  passage  through  it,  from  the  right  to  the  left,  is 
at  that  time  oblique,  and  from  below  upwards. 

The  theory  of  Sabatier  appears  to  be  this;  The  um- 
bilical vein  brings  from  the  placenta  blood  which  has  a 
quality  essential  to  the  animation  of  the  fcetus.  If  there 
were  no  particular  provision  to  the  contrary,  a large 
portion  of  this  blood,  after  passing  from  the  umbilical 
vein  by  the  inferior  cava  into  the  right  auricle  of  the 
heart,  would  proceed  by  the  right  ventricle,  through  the 
pulmonary  artery  and  arterial  canal,  into  the  aorta,  below 
the  origins  of  the  carotid  and  subclavian  arteries;  and 
consequently  none  of  it  would  pass  to  the  head  and  upper 
extremities,  but  a considerable  part  would  return  again 
by  the  umbilical  arteries  to  the  placenta,  without  circulat- 
ing through  the  bod}’:  while  on  the  other  hand,  the  blood 
which  passed  by  the  carotid  and  subclavian  arteries  to 
the  head  and  upper  extremities,  returning  from  them  to 
the  heart  by  the  superior  cava,  might  pass  from  the  right 
auricle  to  the  left  auricle  and  ventricle  and  the  aorta,  and 
so  to  the  head  and  upper  extremities  again,  without  pass- 
ing through  the  placenta.  But  by  means  of  this  valve,  the 
blood  of  the  lower  cava,  and  of  course  of  the  umbilical 
vein,  is  directed  to  the  left  auricle  and  ventricle  and  the 
aorta,  by  which  a considerable  portion  ot  it  will  necessa- 
rily pass  to  the  head  and  upper  extremities:  while  the 
blood  which  returns  from  these  parts  by  the  supe- 
rior cava,  must  consequently  pass  from  the  right  au- 


75 


respecting  the  Festal  Circulation. 

ricle  into  the  right  ventricle  and  pulmonary  artery;  from 
whence  a large  portion  of  it  will  proceed  through  the 
arterial  canal  into  the  aorta  beyond  the  carotids  and  sub- 
calvians,  and  of  this  portion  a considerable  part  will  go 
to  the  placenta  by  the  umbilical  arteries.  Sabatier  com- 
pares the  course  of  the  blood  in  the  foetus  to  the  course' 
of  a fluid  in  a tube  which  has  the  form  of  the  numeral 
character  8.* — If  this  doctrine  be  true,  the  progress  of 
the  blood  in  the  foetus  and  placenta  is  very  analogous  to 
that  of  the  double  circulation  of  the  adult;  the  character  8 
answering  equally  well  in  the  description  of  either  sub- 
ject. 

According  to  Sabatier,  the  blood  of  the  placenta  takes 
this  peculiar  course  through  the  heart,  in  order  that  some 
of  it  may  be  carried  to  the  head  and  upper  extremities. 
But  an  additional  reason  may  be  suggested,  which  ap- 
pears to  be  of  great  importance;  viz.  the  supplying  of 
the  coronary  or  proper  vessels  of  the  heart  with  some  of 
the  same  blood. 

The  heart  of  the  adult,  as  has  been  before  stated,  can- 
not act  without  its  proper  or  coronary  arteries  are  sup- 
plied with  arterial  blood.  The  heart  of  the  feetus  per- 
forms a more  extensive  circulation  than  that  of  the 
adult,  and  therefore  is  probably  in  greater  need  of  such 
blood.  But  unless  the  blood  of  the  placenta  passes  through 
the  foramen  ovale  into  the  left  auricle  and  ventricle , and 
so  to  the  aorta , it  cannot  enter  the  coronary  arteries  which 
riginate  at  the  commencement  of  the  aorta;  for  the  blood 
which  flows  from  the  right  side  of  the  heart  through  the 
arterial  canal,  passes  into  the  aorta  at  so  great  a dis- 
tance from  the  orifices  of  the  coronary  arteries,,  that  it 
certainly  cannot  enter  them. 

The  whole  of  this  doctrine  seems  to  be  supported  by 
a fact,  very  familiar  to  accoucheurs,  viz.  the  occurrence 
of  death  in  the  foe; us  whenever  the  circulation  through 
the  umbilical  cord  is  suspended  during  fifteen  or  twenty 
minutes:  for  as  the  placenta  imparts  to  the  foetal  blood 

* See  Sabatier’s  Paper  on  this  subject  in  the  Memoirs  of  the  Aca- 
demy of  Sciences,  for  1774. 


76 


Unusual  Cases  of  Malformation. 

a quality  essential  to  life,  some  arrangement  seems  ne- 
cessary to  provide  for  the  equal  distribution  of  the 
blood  which  comes  from  this  organ,  and  especially  for 
carrying  the  requisite  proportion  of  it  to  the  substance 
of  the  heart. 


Life  has  existed  for  some  time  with  a structure  very  dif- 
ferent indeed  from  that  which  is  natural.  In  the  series 
of  elegant  engravings  relating  to  morbid  anatomy,  pub- 
lished by  Dr.  Baillie,  is  the  representation  of  a heart, 
in  which  the  venae  cavae  opened  into  the  right  auricle, 
and  the  pulmonary  veins  into  the  left  auricle,  in  the 
usual  mannei ; but  the  aorta  arose  entirely  from  the 
right  ventricle,  and  the  pulmonary  artery  as  completely 
from  the  left. — The  canalis  arteriosus,  however,  passed 
from  the  pulmonary'  artery  to  the  aorta,  and  the  fora- 
men ovale  existed.  In  this  case  it  is  evident  that  the 
pulmonary  artery  must  have  carried  back  to  the  lungs 
tne  arterial  blood  which  came  from  them  by  the  pulmo- 
nary veins,  with  a small  quantity  of  venous  blood  that 
passed  into  the  left  auricle  through  the  foramen  ovale; 
and  that  the  aorta  must  have  returned,  to  the  body,  the 
venous  blood  which  just  before  had  been  brought  from 
it  by  the  venae  cavae,  with  a small  addition  of  arterial 
blood  that  passed  through  the  ductus  arteriosus.  Yet, 
with  this  structure,  the  child  lived  two  months  after  its 
birth. 

A case,  which  had  a strong  resemblance  to  the  fore- 
going, occurred  lately  in  Philadelphia,  and  was  examin- 
ed by  the  author  of  this  work.  The  venae  cavae  terminat- 
ed regularly  in  the  right  auricle,  and  the  pulmonary 
veins  in  the  same  regular  manner  in  the  left;  but  the 
pulmonary  artery  arose  from  the  left  ventricle,  and  the 
aorta  from  the  right.  There  was  no  communication  be- 
tween these  vessels  by  a canalis  arteriosus;  but  a large 
opening  existed  in  the  septum  between  the  auricles. 

It  is  very  evident,  that  in  this  case  also  the  pulmonary 
artery  must  have  returned  to  the  lungs  the  arterial  blood 
as  it  came  from  them,  and  the  aorta  must  have  carried 
back  to  the  general  system  the  venous  blood  brought  to 


Foramen  Ovale. 


17 

the  heart  by  the  cavae;  excepting  only  those  portions  of 
the  arterial  and  venous  blood  which  must  have  flowed 
reciprocally  from  one  auricle  into  the  other,  and  thus 
changed  their  respective  situations. 

The  subject  was  about  two  years  and  a half  old.  The 
heart  was  nearly  double  the  natural  size,  and  the  fora- 
men, or  opening  in  the  septum  between  the  auricles, 
was  eight  or  nine  lines  in  diameter.  The  pulmonary  ar- 
tery was  larger  in  proportion  than  the  aorta  or  the  heart. 

With  this  organization  the  child  lived  to  the  age 
above  specified.  His  countenance  was  generally  rather 
livid;  and  this  colour  was  always  much  increased  by  the 
least  irregularity  of  respiration.  His  nails  were  always 
livid.  He  sometimes  appeared  placid,  but  more  fre- 
quently in  distress.  He  never  walked,  and  seldom,  if 
ever,  stood  on  his  feet.  When  sitting  on  the  floor,  he 
would  sometimes  push  himself  about  the  room;  but  this 
muscular  exertion  always  greatly  affected  his  respira- 
ration.  He  attained  the  size  common  to  children  of  his 
age,  and  had  generally  a great  appetite.  For  some 
weeks  before  death  his  legs  and  feet  were  swelled. 

It  is  probable  that  the  protraction  of  life  depended 
upon  the  mixture  of  the  blood  in  the  two  auricles;  and 
that  they  really  were  to  be  considered  as  one  cavity,  in 
this  case. 


There  seems  reason  to  believe,  that  in  adults  of  the  com- 
mon structure,  there  is  no  passage  of  blood  from  one 
auricle  to  the  other,  when  the  foramen  ovale  has  re- 
mained open;  because  in  several  persons  in  whom  it 
was  found  by  dissection  to  have  remained  open,  there 
were  no  appearances  during  life  that  indicated  the  pre- 
sence of  disoxygenated  blood  in  the  aortic  system.  It  is 
probable,  that  the  small  size  of  the  foramen  ovale,  the 
valvular  structure  which  generally  exists  there,  and  the 
complete  occupation  of  the  left  auricle  by  the  blood 
flowing  from  the  pulmonary  veins,  prevent  the  passage 
of  blood  from  the  right  auricle  to  the  left,  in  such  per- 
sons; whereas,  in  the  case  in  question,  the  opening  be- 
tween the  auricles  was  very  large  indeed,  and  there  was 
no  appearance  of  a valve  about  it. 


78  On  the  Source  of  the  Motion  of  the  Heart. 

Although  it  be  admitted,  that  in  adults  with  the  fora- 
men ovale  pervious,  there  is  no  transmission  of  blood 
from  the  right  to  the  left  auricle;  there  is  every  reason 
to  believe  that  this  transmission  goes  on  steadilv  in  the 
fcerus.  To  the  arguments,  derived  from  the  structure 
and  the  nature  of  the  case,  it  may  be  added,  that  the 
pulmonary  veins,  in  the  foetal  state,  carry  to  the  left  au- 
ricle a quantity  of  blood,  not  sufficient  to  fill  it;  while 
the  venae  cavse  carry  to  the  right  auricle  not  onlv  the 
whole  blood  of  the  body,  but  of  the  umbilical  cord  and 
placenta:  some  of  which  must  flow  into  the  unfilled  left 
auricle,  when  the  right  auricle  becomes  fully  distended. 


The  question  how  far  the  functions  of  the  heart  and  lungs 
are  dependent  upon  the  brain  is  very  important,  and 
has  often  been  agitated  with  great  zeal.  In  favour  of 
the  opinion  that  the  motions  of  the  heart  are  inde- 
pendent of  the  brain,  may  be  stated  the  numerous  cases 
in  which  the  brain  has  been  deficient  in  children,  who 
have  notwithstanding  lived  the  full  period  of  utero  ges- 
tation, and  even  a short  time  after  birth,  and  have  ar- 
rived at  their  full  size,  with  every  appearance  of  perfect 
vigour  and  action  in  the  heart.  In  support  of  the  doc- 
trine, that  the  action  of  the  heart  is  immediately  de- 
pendent upon  the  brain,  it  may  be  observed,  that  no 
organ  of  the  body  appears  to  be  so  much  influenced  by 
passions  and  other  mental  affections  as  the  heart.  These 
contradictory  facts  have  occasioned  this  question  to  be 
considered  as  undecided,  if  not  incapable  of  solution; 
although  Cruikshank  and  Bichat*  have  stated  circum- 
stances very  favourable  to  the  opinion  that  the  motions 
of  the  heart  are  independent  of  the  brain. 

* See  Cruikshank’s  Experiments  on  the  Nerves  and  Spinal  Mar- 
row ofliving  animals;  London  Philosophical  Transactions  for  1795. 
The  eighth  experiment  has  a particular  relation  to  this  subject. 

Bichat’s  Researches,  part  2,  article  9. 

The  Abbe  Eontana  has  considered  this  subject  in  his  Treatise  on 
the  Venom  of  the  Viper,  vol.  ii.  page  194,  English  translation;  and 
also  in  some  of  his  other  works. 


Humboldt  and  others  on  Legallois ’ Paper.  79 

This  question  seems  now  to  be  settled  by  the  experi- 
ments of  Dr.  Legallois,  a physician  of  Paris,  which 
prove,  that  in  animals  who  have  suffered  decapitation , 
the  action  of  the  heart  does  not  cease  as  an  immediate 
consequence  of  the  removal  of  the  head;  but  its  cessa- 
tion is  an  indirect  effect , induced  by  the  suspension  of 
respiration.  That  respiration  is  immediately  affected  by 
decapitation,  and  depends  upon  the  influence  of  the 
brain  transmitted  through  the  eighth  pair  of  nerves. 
That  the  action  of  the  heart  will  continue  a long  time 
after  decapitation,  if  inflation  of  the  lungs,  or  artificial 
respiration,  be  performed;  but,  on  the  contrary,  if  the 
spinal  marrow  be  destroyed,  the  action  of  the  heart 
ceases  irrecoverably. 

The  inference  from  these  experiments  seems  very 
conclusive,  that  the  Spinal  Marrow , and  not  the  brain,  is 
the  source  of  the  motions  of  the  heart. 

It  appears  also  by  some  of  the  experiments,  that  the 
power  of  motion  in  the  trunk  of  the  body  is  derived  from 
the  spinal  marrow;  and  that  when  this  organ  is  partially 
destroyed,  the  parts  which  receive  nerves  from  the  de- 
stroyed portion  soon  cease  to  live.  By  particular  man- 
agement of  the  spinal  marrow,  one  part  of  the  body  can 
be  preserved  alive  for  some  time  after  the  other  parts  are 
dead. 

These  experiments  of  Dr.  Legallois  commenced  in  1806 
or  1807,  and  were  communicated  to  the  Imperial  Insti- 
tute of  France  in  1811.  The  committee  of  that  body 
to  whom  they  were  referred,  viz.  Messrs.  Humboldt, 
Halle  and  Percy,  reported  that  the  experiments  had  been 
repeated  before  them,  at  three  different  meetings  of  se- 
veral hours  each;  and  that  to  allow  themselves  sufficient 
time  for  reflection,  they  suffered  an  interval  of  a week 
to  take  place  bettveen  the  meetings.  The  committee  be- 
lieve these  experiments  to  have  proved, 

1st.  That  the  principle  upon  which  all  the  movements 
of  inspiration  depend,  has  its  seat  about  that  part  of  the 
medulla  oblongata  from  which  the  nerves  of  the  eighth 
pair  arise. 

2d.  That  the  principle  which  animates  each  part  of  the 


80  Brodie  on  the  Source  of  the  Motion  of  the  Heart. 

trunk  of  the  body  is  seated  in  that  portion  of  the  spinal 
marrow  from  which  the  nerves  of  the  part  arise. 

3d.  That  the  source  of  the  life  and  strength  of  the 
heart  is  also  in  the  spinal  marrow;  not  in  any  distinct 
portion,  but  in  the  whole  of  it. 

4th.  That  the  great  sympathetic  nerve  is  to  be  consi- 
dered as  originating  in  the  spinal  marrow,  and  that  the 
particular  character  of  this  nerve  is  to  place  each  of  the 
parts  to  which  it  is  distributed  under  the  immediate  in- 
fluence of  the  whole  nervous  power. 

The  interesting  memoir  of  Dr.  Legallois  is  confirmed  to  a 
certain  degree  by  a communication  of  B.  C.  Brodie  to 
the  Royal  Society  of  London  in  1810,  in  which  are  de- 
tailed many  very  interesting  experiments  which  induced 
the  author  to  conclude, — 

That  the  influence  of  the  brain  is  not  directly  neces- 
sary to  the  action  of  the  heart;  and 

That  when  the  brain  is  injured  or  removed,  the  ac- 
tion of  the  heart  ceases,  onlv  because  respiration  is  un- 
der its  influence;  and  if  under  these  circumstances  res- 
piration is  artificially  produced,  the  circulation  will  still 
continue. 

These  various  experiments  apply  particularly  to  the  cases 
in  which  the  brain  is  deficient,  ifhe  effects  of  mental 
agitations  on  the  heart  are  likewise  reconcileable  to  the 
theory  which  arises  out  of  them.  But  they  throw  no 
light  on  the  question  why  the  motions  of  the  heart  are 
so  perfectly  free  from  the  influence  of  the  will:  and  al- 
though they  seem  to  prove  incontestably  that  the  mo- 
tion of  the  heart  is  independent  of  the  brain,  it  ought 
to  be  remembered  that  in  certain  diseased  states  of  the 
brain,  where  that  organ  appears  to  be  compressed,  the 
action  of  the  heart  is  often  very  irregular,  and  its  con- 
tractions less  frequent  than  usual. 


SYSTEM  OF  ANATOMY. 


PART  VIII, 


OP  THE  ABDOMEN. 

THE  lowermost  of  the  two  great  cavities  of  the  trunk 
of  the  body  is  called  Abdomen . The  pelvis  may  be  consi- 
dered as  a chamber  of  this  cavity,  although  its  structure  is 
very  different. 


CHAPTER  I. 

A GENERAL  VIEW  OF  THE  ABDOMEN  AND  PELVIS  AND  THEIR 
CONTENTS,  WITH  AN  ACCOUNT  OF  THE  PERITONEUM. 

SECTION  I. 

Of  the  Abdomen. 

THIS  great  cavity  occupies  more  than  half  of  the  space 
inclosed  by  the  ribs,  and  all  the  interior  of  the  trunk  of  the 
body  below  the  thorax. 

It  is  formed  by  the  diaphragm,  supported  by  the  lower 
ribs;  by  a portion  of  the  spine;  by  the  various  muscles 
which  occur  between  the  lower  margin  of  the  thorax  and 
the  upper  margin  of  the  ossa  innominata;  and  by  the  ossa 
innominata,  which  contribute,  for  the  purpose,  the  costas  of 
the  ossa  ilea,  as  well  as  the  pelvis. 

Voii.  II.  L 


82 


Construction  of  the  Abdomen. 

The  general  figure  of  this  cavity  partakes  of  the  figure 
of  the  lower  part  of  the  trunk  of  the  body;  with  these  ex- 
ceptions, that  the  diaphragm  makes  it  arched  or  vaulted 
above,  that  the  spine  and  psoas  muscles,  &c.  are  rather 
prominent  on  the  posterior  surface,  and  that  the  lower 
part  corresponds  with  the  costae  of  the  ossa  ilea  and  with 
the  pelvis. 

To  acquire  a precise  idea  of  this  cavity,  it  is  necessary 
first  to  study  the  bones  concerned  in  its  structure,  in  their 
natural  situation  in  the  skeleton;  and  then  the  muscles, 
which  form  so  large  a part  of  it. 

The  arrangement  of  the  tendons  of  some  of  these  mus- 
cles, with  a view  to  complete  the  cavity,  is  particularly 
interesting;  as  that  of  the  external  oblique  when  it  forms 
the  crural  arch.*  The  ligaments  of  the  pelvis  and -the  le- 
vatores  ani  muscles,  as  they  also  contribute  to  the  forma- 
tion of  the  cavity,  and  have  an  influence  upon  its  figure, 
should  likewise  be  attended  to. 

In  the  walls  of  the  cavity,  thus  constructed,  there  are 
many  foramina  by  which  the  viscera  and  other  contained 
parts  communicate  externally;  but  few  of  them  pass  di- 
rectly into  the  cavity;  for  like  the  thorax’  there  are  no  va- 
cuities in  it  exterior  to  the  contained  organs. 

Three  of  these  foramina  are  in  the  diaphragm.  One  for 
the  transmission  of  the  aorta,  another  for  the  vena  cava, 
and  a third  for  the  oesophagus.  Below,  there  is  an  aperture 
at  each  of  the  crural  arches,  for  the  transmission  of  the 
great  femoral  vessels;  in  each  of  the  ligamentous  mem- 
branes, which  close  the  foramen  thyroidcum,  for  .the  obtu- 
rator vessels  and  nerve;  and  at  the  sacro  sciatic  notches, 
for  nerves  and  bloodvessels. 

There  are  also  two  apertures  at  the  bottom  of  the  pel- 
vis, for  the  orifice  of  die  rectum  and  of  the  urethra.  In  the 
tendons  of  the  external  oblique  muscles- are  two  orifices^ 

* See  the  account  of  this  tendon,  vol.  i.  in  the  description  of  the 
“ Obliquus  Decendens  Lxternus.” 


83 


Construction  of  the  Abdomen. 

covered  by  the  integuments,  for  the  spermatic  cords;  and, 
in  the  foetal  state,  one  for  the  umbilical  cord. 

The  apertures  in  the  tendons,  and  under  their  edges, 
for  the  transmission  of  the  spermatic  cords,  and  the  blood- 
vessels, See.  are  not  to  be  considered  as  simple  perfora- 
tions made  abruptly;  but  the  edges  of  these  foramina  are 
formed  by  tendinous  membranes  turned  inwards  and  con- 
tinued so  as  to  compose  a cylindrical  tube,  which  becomes 
gradually  so  thin  that  it  cannot  be  readily  distinguished 
from  the  cellular  membrane  with  which  it  is  connected.* 
The  bloodvessels,  &c.  pass  along  this  tube  before  they  go 
through  the  apertures. 

It  is  evident  from  the  construction  of  this  cavity  that 
it  is  essentially  different  from  the  thorax.  It  has  no  power 
of  spontaneous  dilatation  whatever:  it  yields  passively  to 
the  distension  of  the  stomach  and  intestines,  during  deglu- 
tition, and  when  air  is  extricated  from  the  aliment,  &c.; 
but  it  is  particularly  calculated  for  compressing  its  con- 
tents by  the  contraction  of  the  muscles  which  compose  it. 
The  diminution  of  its  capacity,  which  is  thus  effected, 
not  only  takes  place  to  a great  degree,  but  occasionally 
with  great  force.  The  diaphragm  and  the  abdominal  mus- 
cles may  be  considered  in  some  measure  as  antagonists 
of  each  other.  When  the  diaphragm  descends,  if  the  ab- 
dominal muscles  are  passive,  they  are  distended  by  the 
contents  of  the  abdomen,  which  are  forcibly  pressed  from 
above;  but  if  the  abdominal  muscles  act  at  the  same  time, 
an  effort  to  diminish  the  cavity  in  every  direction  takes 
place,  and  the  contained  parts  are  compressed  with  more 
or  less  force  according  to  the  exertion  made.  This  will 
be  very  evident  upon  examining  the  situation  of  the  dia- 
phragm and  of  the  abdominal  muscles.  When  their  force 

* The  student  of  anatomy,  when  engaged  with  this  subject,  will 
be  gratified  by  the  examination  of  Mr.  Astley  Cooper’s  plates  rela 
ting  to  hernis. 


84 


Contents  of  the  Abdomen. 

is  considered  it  will  also  be  very  obvious  that  the  various 
outlets  of  the  cavity  are  constructed  most  advantageously; 
otherwise  hernia  or  protrusion  of  its  contents  would  be  a 
daily  occurrence. 

The  abdomen  contains,  1st.  The  Stomach  and  the  whole 
Intestinal  Tube , consisting  of  the  small  and  the  great  in- 
testines. 

2d.  The  Assisting  Chylopoietic  Viscera , — the  Liver,  the 
Pancreas  and  the  Spleen. 

3d.  The  Urinary  Organs, — the  Kidneys,  the  Ureters, 
and  the  Bladder.  To  which  should  be  added  the  Glandu- 
lar Renales. 

4th.  The  Organs  of  Generation  in  part:  those  of  the 
female  sex  being  almost  wholly  included  in  the  pelvis; 
and  those  of  the  male  being  situated  partly  within  and 
partly  without  it. 

5th.  The  Peritoneum  and  its  various  processes.  The 
Mesentery,  Omentum,  &c. 

6th.  A portion  of  the  Aorta,  and  almost  the  whole  of  the 
Inferior  Cava , and  their  great  ramifications;  with  such  of 
their  branches  as  are  appropriated  to  the  Viscera  of  the 
Abdomen  and  Pelvis. 

7th.  Those  portions  of  the  Par  Vagum  and  Intercostal 
Nerves  which  are  appropriated  to  the  cavity;  and  portions 
of  some  of  the  nerves  destined  to  the  lower  extremities. 

8th.  The  lower  part  of  the  Thoracic  Duct , or  the  Great 
Trunk  of  the  Absorbent  System,  with  the  large  branches 
that  compose  it,  and  the  glands  connected  with  them;  and 
also  those  absorbent  vessels  called  Lacteals , and  their 
glands. 

As  the  cavity  of  the  abdomen  has  no  natural  divisions, 
anatomists  have  divided  it  by  imaginary  lines  into  various 
regions,  with  a view  to  precision  in  their  accounts  of  the 
situation  of  the  different  contained  parts.  Thus, 

They  have,  very  generally,  agreed  to  apply  two  trans- 
verse lines  to  form  three  great  divisions;  viz.  the  Upper , 


85 


Regions  of  the  Abdomen. 

Middle  and  Lower:  and  they  have  also  agreed  that  each  of 
these  divisions  shall  be  subdivided  into  three  regions. 

The  three  regions  of  the  uppermost  division  are  defined 
with  some  precision.  Those  on  each  side,  which  are  called 
the  Right  and  Left  Hypochondriac  regions , occupy  the 
spaces  immediately  within  the  lower  ribs  and  their  carti- 
lages; while  the  middle  space,  included  within  the  margins 
of  these  cartilages,  and  a line  drawn  from  the  lower  edge  of 
the  thorax  on  one  side  to  that  on  the  other,  is  denomina- 
ted the  Epigastric  region. 

The  boundaries  of  the  regions  below  are  less  precisely 
defined. 

Many  anatomists  have  fixed  the  two  transverse  lines 
above  mentioned  at  an  arbitrary  distance  above  and  below 
the  umbilicus;  some  choosing  for  this  purpose  two  inches, 
and  others  a hand’s  breadth.  As  these  distances  will  occu- 
py different  proportions  of  the  cavity  in  persons  of  differ- 
ent stature,  other  anatomists,  with  a view  to  avoid  this 
inconvenience,  have  proposed  to  connect  these  lines  with 
certain  fixed  points  of  the  skeleton. 

It  is  of  importance  that  the  boundaries  of  these  regions 
should  be  fixed,  and  therefore  the  proposition  of  Sabatier 
may  be  adopted;  viz.  To  draw  the  upper  transverse  line 
from  the  most  inferior  part  of  the  lower  margin  of  the 
thorax,  on  one  side,  to  the  corresponding  part  on  the  oppo- 
site side;  and  the  lower  transverse  line  from  the  upper- 
most part  of  the  spine  of  one  ileum  to  the  same  part  of  the 
other.  These  lines  will  mark  the  three  great  divisions.  If 
then  two  parallel  lines  are  drawn  directly  upwards,  one 
from  each  of  the  superior  anterior  spinous  processes  of  :he 
ileum  until  it  touches  the  lower  margin  of  the  thorax 
they  will  divide  each  of  the  two  lower  divisions  of  the 
abdomen  into  three  regions.  The  center  of  the  middle 
division  is  the  umbilical,  and  on  each  side  of  it  is  the  right 
and  left  lumbar  region.  The  middle  of  the  lower  division 


86  Situation  of  the  Viscera , fcfc.  in  the 

is  the  hypogastric;  and  on  each  side  of  it  the  right  and 
left  iliac  region. 

It  is  true,  that  the  three  middle  regions  of  the  abdomen 
will  be  made  very  small  by  the  vicinity  of  the  transverse 
lines  to  each  other;  but  the  advantages  derived  from  a 
principle  which  is  similar  in  its  application  to  all  subjects 
fully  compensates  this  inconvenience. 

There  are  therefore  nine  of  these  regions:  viz.  The 
Epigastric  and  the  two  Hypochondriac:  the  Umbilical, 
and  the  two  Lumbar:  the  Hypogastric,  and  the  two  Iliac 
regions.*  And  it  should  be  added,  that  the  space  imme- 
diately around  the  end  of  the  sternum  is  sometimes  cal- 
led the  Scrobiculus  Cordis;  and  the  space  immediately 
within  the  os  pubis,  the  Regio  Pubis . 

These  different  regions  are  generally  occupied  in  the 
following  manner.  The  liver  fills  nearly  the  whole  of  the 
rig  it  hypochondriac  region,  and  extends  through  the  up- 
per part  of  the  epigastric  region  into  the  left  hypochon- 
driac. The  stomach  occupies  the  principal  part  of  the  epi- 
gastric region,  and  a considerable  portion  of  the  left  hy- 
pochondriac. The  spleen  is  also  situated  in  the  left  hypo- 
chondriac region.  That  portion  of  the  intestinal  tube, 
which  is  composed  of  the  small  intestines,  is  generally 
found  in  the  umbilical,  the  hypogastric,  and  the  iliac  re- 
gions; and  when  the  bladder  is  empty,  in  the  pelvis.  But 
the  duodenum,  or  first  of  the  small  intestines,  which  pro- 
ceeds immediately  from  the  stomach,  is  situated  in  the 
epigastric  and  umbilical  regions.  The  great  intestine 
commences  in  or  near  the  right  iliac  region,  and  ascends 
through  the  right  lumbar  to  the  right  hypochondriac  re- 
gion. It  then  crosses  the  abdomen,  passing  through  the 
lower  part  of  the  epigastric,  or  upper  part  of  the  umbilical 

• It  is  to  be  observed  that  the  lateral  regions  of  the  middle  and 
lower  divisions  of  the  abdomen  are  named  differently  by  different 
writers. 


87 


Cavity  of  the  Abdomen. 

to  the  left  lumbar  region;  from  this  it  continues  into  the 
left  iliac  region,  and  curves  in  such  manner  that  it  finally 
arrives  at  the  middle  of  the  upper  part  of  the  os  sacrum, 
when  it  descends  into  the  pelvis,  and,  partaking  of  the 
curvature  of  the  last  mentioned  bone,  continues  to  the 
termination  of  the  os  coccygis. 

In  the  back  part  of  the  epigastric  region,  and  very 
low  down  in  it,  is  situated  the  pancreas.  The  kidneys  lie 
in  the  most  posterior  parts  of  the  lumbar  regions,  and 
from  each  of  them  is  continued  a tube  or  duct,  called 
Ureter , that  passes  into  the  pelvis  to  convey  the  urine  to 
the  bladder.  This  viscus,  in  males,  is  in  contact  with  the 
last  portion  of  the  great  intestine  called  the  Rectum , and 
with  it  occupies  almost  all  of  the  cavity  of  the  pelvis; 
while  in  females,  the  uterus  and  its  appendages  are 
situated  between  this  intestine  and  the  bladder. 

In  the  posterior  part  of  the  abdomen,  in  contact  with 
the  spine,  is  the  aorta.  This  great  bloodvessel  passes 
from  the  thorax  between  the  crura  of  the  diaphragm, 
and  continues  down  the  spine  until  it  approaches  towards 
the  pelvis,  when  it  divides  into  two  great  branches  called 
the  Iliac  Arteries.  Each  of  these  great  branches  divides 
again,  on  the  side  of  the  pelvis,  into  two;  viz.  the  Ex- 
ternal Iliac , which  passes  under  the  crural  arch  to  the 
thigh,  and  the  Internal  Iliac , or  Hypogastric , which  de- 
scends into  the  cavity  of  the  pelvis. 

Soon  after  the  arrival  of  the  aorta  in  the  abdomen  it 
gives  off  two  large  branches.  The  first,  which  is  called 
the  Cceliac,  is  distributed  to  the  liver,  the  stomach,  and 
the  splcjen:  the  second,  called  the  Superior  Mesenteric , 
is  spent  upon  the  intestines.  Lower  down,  in  the  abdo- 
men, it  also  sends  off  a small  branch  for  the  intestines, 
called  the  Inferior  Mesenteric.  Besides  these  vessels  for 
the  chylopoietic  viscera,  the  aorta  sends  of  a large 
branch,  called  Einulgent , to  each  kidney. 

The  inferior,  or  ascending  vena  cava,  is  situated  on 


88 


The  Peritoneum. 


the  right  of  the  aorta,  in  front  of  the  spine.  It  is  formed 
below  by  the  union  of  the  iliac  veins,  and  in  its  progress 
upwards  it  receives  the  emulgent  veins,  which  corres- 
pond to  the  arteries  of  the  kidneys;  but  it  receives  in 
its  course  no  veins  which  correspond  directly  with  the 
coeliac  and  mesenteric  arteries.  The  smaller  veins,  that 
answer  to  the  branches  of  these  arteries,  unite  and  form 
one  large  vein,  which  goes  to  the  liver,  and  is  called 
(from  the  part  of  that  viscus  at  which  it  enters)  Vena 
Portarum.  From  the  liver  three  large  veins  pass  into  the 
vena  cava,  and  deposit  there  the  blood  of  the  vena  por- 
tarum, after  it  has  furnished  materials  for  the  secretion 
of  bile.  The  vena  cava,  in  its  passage  upwards,  is  in 
close  contact  with  the  posterior  thick  edge  of  the  liver: 
it  often  passes  along  a deep  groove  in  this  edge,  and 
sometimes  it  is  completely  surrounded  by  the  liver  in  its 
course.  The  veins  of  the  liver  enter  the  vena  cava  at  this 
place,  and  of  course  they  are  not  to  be  seen  without  dis- 
section. Immediately  after  leaving  the  liver  the  vena 
cava  passes  through  an  aperture  in  the  tendinous  center 
of  the  diaphragm  to  unite  itself  to  the  right  auricle  of  the 
heart. 


1 


SECTION  II. 

Of  the  Peritoneum . 

THE  abdomen,  thus  constructed  and  occupied,  is 
fined  by  a thin  firm  membrane  called  Peritoneum , which 
is  extremely  smooth  on  its  internal  surface,  and  is  inti- 
mately connected  with  the  cellular  substance  exterior  to 
it.  This  membrane  adheres  closely  to  the  anterior,  lateral, 
and  superior  portions  of  the  surface  of  the  abdomen;  and 
is  extended  from  the  posterior  surface  so  as  to  cover, 


The  Peritoneum. 


89 


more  or  less  completely,  the  viscera  of  the  cavity.  Those 
viscera  which  are  in  close  contact  with  the  posterior  sur- 
face of  the  abdomen,  as  some  portions  of  the  large  in- 
testine, are  covered  only  on  their  anterior  surfaces,  and 
are  fixed  in  their  precise  situations  by  the  peritoneum; 
which  extends  from  them  to  the  contiguous  surface  of 
the  cavity,  and  adheres  where  it  is  in  contact,  so  as  to 
produce  this  effect. 

Other  viscera,  which  are  not  in  close  contact,  but 
moveable  to  a distance  from  the  posterior  surface  of  the 
abdomen,  are  covered  by  this  membrane,  which  is  extend- 
ed to  them  from  the  surface;  and  this  extended  portion 
forms  an  important  part  of  the  connexion  between  the 
viscus  and  the  cavity  in  which  it  lies.  This  connecting 
part  is  called  Mesentery , when  it  thus  passes  to  the  small 
intestines;  Mesocolon , when  it  goes  to  the  colon,  one  of 
the  larger  intestines;  and  Ligament , when  it  passes  to 
some  of  the  other  viscera. 

The  peritoneum  is  a complete  but  empty  sac,  which 
is  fixed  in  the  abdomen  anterior  to  the  viscera.  The  an- 
terior portion  of  this  sac  forms  the  lining  to  the  ante- 
rior and  lateral  parts  of  the  surface  of  the  abdomen;  the 
posterior  portion  covers  the  viscera,  and  forms  the  me- 
sentery, mesocolon,  and  ligaments  above  described. 

It  necessarily  follows  that  the  mesentery  and  the  other 
similar  processes  are  mere  plaits  or  folds  of  the  sac,  which 
invests  the  viscera;  and  that  they  must  consist  of  two  la- 
minae: and  as  the  bloodvessels,  nerves,  and  absorbents, 
are  all  posterior  to  the  peritoneum,  they  naturally  pass 
between  these  laminae  of  the  mesentery. 

Some  of  the  viscera  are  much  more  completely  invest- 
ed with  the  peritoneum  than  others.  The  stomach,  liver, 
and  spleen,  are  almost  completely  surrounded  by  it;  and 
it  is  said  to  form  a coat  for  each  of  these  viscera.  That 
portion  of  the  smaller  intestinal  tube,  which  is  called  je- 
junum and  ileum , and  the  transverse  portion  of  the  large 

Vol.  II.  M 


90 


The  Peritoneum. 


intestine,  called  the  arch  of  the  colon , are  invested  by  it 
in  the  same  way.  But  a considerable  portion  of  the  duo- 
denum and  the  pancreas  is  behind  it.  The  lateral  portions 
of  the  colon  are  in  close  contact  with  the  posterior  sur- 
face of  the  abdomen,  and  the  peritoneum  only  covers  that 
portion  of  their  surfaces  which  looks  anteriorly  towards 
the  cavity  of  the  abdomen,  and  is  not  in  contact  with  its 
posterior  surface. 

The  urinary  organs  are  not  much  connected  with  the 
peritoneum.  The  kidneys  appear  exterior  to  it,  and  be- 
hind it:  the  bladder  of  urine  is  below  it,  and  has  but  a 
partial  covering  from  it,  on  its  upper  portion. 

The  peritoneum,  which  covers  the  stomach,  is  ex- 
tended from  the  great  curvature  of  that  organ  so  as  to 
form  a large  membrane,  which  descends  like  an  apron 
before  the  intestines.  This  process  of  peritoneum  is  com- 
posed of  two  laminae,  so  thin  and  delicate  as  to  resemble 
cellular  membrane,  which,  after  extending  downwards 
to  the  lower  part  of  the  abdomen,  are  turned  backwards 
and  upwards,  and  proceed  in  that  direction  until  they 
arrive  at  the  colon,  which  they  inclose,  and  then  continue 
to  the  back  of  the  abdomen,  forming  the  mesocolon. 
The  part  of  this  process  which  is  between  the  stomach 
and  the  colon,  is  called  Epiploon , or  Omentum. 

This  extension  of  a membrane,  from  the  surface  of  a 
cavity  which  it  lines  to  the  external  surface  of  a viscusin 
that  cavity,  is  called,  by  some  anatomists,  “reflection;” 
and  the  technical  term  refected  membrane  is  therefore  ap- 
plied to  a membrane  distributed  like  the  peritoneum. 

It  must  be  evident  that  this  distribution  of  the  perito- 
neum is  very  complex,  and  that  it  is  not  easy  to  form  an 
accurate  conception  of  it  from  description,  but  it  can  be 
readily  understood  by  demonstration;  therefore  no  fur- 
ther account  of  its  arrangement  will  now  be  attempted, 
but  each  of  its  processes  will  be  considered  with  the  or- 
gans to  which  they  are  particularly  subservient. 


The  Peritoneum. 


91 


That  portion  of  the  peritoneum  which  lines  the  abdo- 
men and  covers  the  viscera  is  thin  and  delicate,  but  very 
firm.  It  yields  to  distention,  as  in  pregnancy,  ascites,  &c.; 
and  again  recovers  its  dimensions.  It  was  formerly  thought 
to  be  composed  of  two  lamina,  but  this  cannot  be  proved. 
The  internal  surface  of  this  membrane  is  very  smooth, 
and  highly  polished;  and  from  it  exudes  a liquor  which 
is  well  calculated  for  lubrication,  and  barely  sutficient  to 
keep  the  surface  moist  during  health;  but  sometimes  it  is 
very  abundant,  and  occasions  the  aforesaid  disease — as- 
cites. This  fluid  appears  to  exude  from  the  surface  of  the 
peritoneum  when  it  is  compressed  in  a living  animal,  or 
in  one  recently  dead.  It  is  probably  effused  from  the  ex- 
tremities of  arteries,  for  an  effusion  takes  place  when  water 
is  injected  into  these  vessels. 

The  peritoneum  abounds  with  absorbent  vessels,  and 
therefore  possesses  the  power  of  absorption  to  a great  de- 
gree. This  power  may  be  inferred,  not  only  from  the  spon- 
taneous removal  of  the  fluid  of  ascites,  but  if  milk  and 
water  be  introduced  into  the  abdomen  of  a living  animal, 
through  a puncture,  it  will  also  disappear. 

The  bloodvessels  of  the  peritoneum  are  derived  from 
those  which  supply  the  neighbouring  parts.  Nerves  have 
not  yet  been  traced  into  it,  and  it  has  little  or  no  sensi- 
bility. 

This  membrane  supports  the  viscera  of  the  abdomen  in 
their  proper  situations;  and  also  forms  a surface  for  them, 
and  for  the  cavity  which  contains  them,  so  smooth  and  lu- 
bricated, that  no  injury  can  arise  from  their  friction. 

The  cellular  substance,  by  which  the  peritoneum  is 
connected  to  the  contiguous  parts,  is  very  different  in  dif- 
ferent places.  It  is  very  short  indeed  between  this  mem- 
brane and  the  stomach  and  intestines,  and  also  between  it 
and  the  tendinous  center  of  the  diaphragm.  Between  the 
peritoneum  and  the  muscles  generally;  it  is  much  longer. 


92 


The  Peritoneum. 


When  it  covers  the  kidneys  and  the  psoas  muscles  it  is 
very  lax  and  yielding.  About  the  kidneys  a large  quan- 
tity of  adeps  very  commonly  collects  in  it.  On  the  psoas 
muscle  it  yields  with  but  little  resistance  to  the  passage  of 
pus,  or  any  other  effused  fluid,  as  in  the  case  of  the  psoas 
abscess. 


93 


CHAPTER  II. 

Of  THE  (ESOPHAGUS,  THE  STOMACH,  AND  THE  INTESTINES'. 

SECTION  I. 

Of  the  (Esophagus. 

THE  (Esophagus  is  a muscular  tube  which  passes  from 
the  pharynx  to  the  stomach,  and  is  so  intimately  connected 
with  the  stomach,  that  it  will  be  advantageous  to  the  stu- 
dent to  attend  to  its  structure  immediately  before  he  en- 
gages in  the  examination  of  that  important  organ. 

The  pharynx  has  been  lately  described*  as  composed  of 
a varied  stratum  of  muscular  fibres,  lined  by  a membrane 
which  is  continued  from  the  internal  surface  of  the  nose 
and  mouth.  From  the  pharynx  the  oesophagus  passes 
downwards  between  the  trachea  and  the  vertebrae.  After 
the  bifurcation  of  the  trachea,  it  proceeds  in  contact  with 
the  spine,  between  the  laminae  of  the  mediastinum,  to  the 
diaphragm,  which  it  passes  through,  and  then  terminates 
in  the  stomach. 

The  oesophagus  is  a flexible  tube,  which,  when  distend- 
ed, is  nearly  cylindrical.  It  consists  of  a muscular  coat 
externally,  and  an  internal  tunic  evidently  continued  from 
that  of  the  pharynx.  These  coats  are  connected  by  a cel- 
lular substance  called  the  Nervous  Coat , which  is  remark- 
ably loose,  and  allows  them  to  move  considerably  upon 
each  other.  The  muscular  coat,  which  is  very  distinguish- 
able from  that  of  the  pharynx,  consists  of  two  substantial 
strata  of  fibres;  the  exterior  of  which  is  nearly  longitudi- 
nal in  its  direction,  and  the  anterior  circular  or  transverse. 


*See  page  37. 


94  The  CEsophagus. 

The  internal  coat  of  the  oesophagus,  resembling  that  of 
the  fauces,  is  soft  and  spongy.  It  is  covered  with  a very 
delicate  cuticle,  which  Haller  supposed  to  be  too  tender 
to  confine  the  matter  of  variolous  pustules,  as  he  had  never 
found  these  extending  into  the  oesophagus.  It  is  very  vascu- 
lar, and  abounds  with  the  orifices  of  mucous  follicles,  from 
which  is  constantly  poured  out  the  mucus  that  is  spread 
over  this  surface.  When  the  oesophagus  is  not  distended, 
many  longitudinal  plaits  are  found  in  this  membrane  by 
the  contraction  of  the  circular  or  transverse  fibres  exterior 
to  it.  These  plaits  are  calculated  to  admit  readily  of  the 
distention  which  is  requisite  in  deglutition.  This  tunic  is 
continued  from  the  lining  membrane  of  the  pharynx  above, 
and  terminates  below  in  the  villous  coat  of  the  stomach; 
from  which,  however,  it  is  very  different. 

The  bloodvessels  of  the  oesophagus  come  from  those 
which  are  in  the  vicinity.  The  nerves  are  derived  from 
the  eighth  pair.  The  lymphatic  vessels  are  very  abundant. 

In  the  neck,  the  oesophagus  inclines  rather  to  the  left  of 
the  middle  line.  As  it  proceeds  down  the  back  between 
the  laminse  of  the  mediastinum,  it  preserves  the  same 
course  to  the  fourth  dorsal  vertebra,  when  it  assumes  the 
middle  portion  and  proceeds  downwards,  with  the  aorta 
to  its  left,  and  the  pericardium  before  it.  About  the  ninth 
dorsal  vertebra  it  inclines  again  rather  to  the  left,  and 
somewhat  forward,  to  arrive  at  the  aperture  in  the  dia- 
phragm through  which  it  passes. 

Throughout  this  course  it  is  connected  by  cellular  mem- 
brane to  the  contiguous  parts;  and  this  investiture  of  cel- 
lular membrane  has  been  called  its  External  Coat. 

While  the  oesophagus  is  in  the  posterior  mediastinum, 
it  is  in  contact  with  several  small  absorbent  glands,  espe- 
cially when  it  first  assumes  a situation  to  the  right  of  the 
aorta.  These  glands  were  formerly  believed  to  be  parti- 
larly  connected  with  this  tube,  but  they  are  now  consi- 
dered as  belonging  to  the  absorbent  system.  They  are 
sometimes  greatly  enlarged. 


Form  of  the  Stomach . 


95 


SECTION  II. 

Of  the  Stomach. 

THIS  most  important  organ,  which  occasionally  ex- 
erts a powerful  influence  upon  every  part  of  the  body, 
appears  very  simple  in  its  structure. 

It  is  a large  sac,  which  is  so  thin  when  much  inflated, 
that  at  first  view  it  seems  membranous,  but  upon  exami- 
tion  is  found  to  be  composed  of  several  lamina  or  coats, 
each  of  a different  structure.  It  is  of  considerable  length, 
but  ineurvated.  It  is  much  larger  at  one  extremity  than 
the  other,  and  changes  so  gradually  in  this  respect,  that 
it  would  appear  conical  if  it  were  straight.  It  is  not,  how- 
ever, strictly  conical,  unless  it  is  greatly  distended;  for 
when  moderately  distended,  a transverse  section  is  rather 
oval  than  circular.  It  is  therefore  considered  as  having 
two  broad  sides  or  surfaces,  and  two  edges,  which  are 
the  curvatures.  It  has  been  compared  by  the  anatomists 
of  different  nations  to  the  wind  sac  of  the  musical  in- 
strument called  the  bag- pipe.*  The  orifice  in  which  the 
oesophagus  terminates  is  at  a small  distance  from  its  large  t 
extremity,  and  is  called  Cardia.  The  orifice  which  com  - 
municates with  the  intestines  is  at  the  termination  of  its 
small  ineurvated  extremity,  and  is  called  the  Pylorus. 

The  two  ends  of  the  stomach  being  thus  very  different 
in  size,  are  denominated  the  great  and  small  extremities. 
The  two  curved  portions  of  the  surface  are  also  called  the 
great  and  small  curvatures.  The  two  flat  portions  of  the 
surface,  or  the  broadsides,  are  called  the  anterior  and  pos- 
terior surfaces. 

The  situation  of  the  stomach  in  the  abdomen  is  nearly 

* The  student  ought  not  to  attempt  to  acquire  an  idea  of  the  form 
of  the  stomach  without  demonstration,  for  a view  of  one  moment 
will  be  more  serviceable  than  a long  description. 


96  Position  of  the  Stomach. 

transverse:  it  lies  principally  in  the  left  hypochondriac 
and  the  epigastric  regions,  immediately  below  the  liver. 
The  great  extremity  of  the  stomach  is  in  the  left  hypo- 
chondriac region,  and  the  lesser  extremity  in  the  epigas- 
tric region,  under  the  left  lobe  of  the  liver.  The  upper 
orifice,  or  Cardia , is  nearly  opposite  to  the  body  of  the 
last  dorsal  vertebra;  and,  owing  to  the  curved  form  of  the 
stomach,  the  other  orifice,  or  Pylorus , is  situated  at  a 
small  distance  to  the  right  of  that  bone,  and  rather  lower 
and  more  forward  than  the  cardia:  both  orifices  being  in 
the  epigastric  region.  The  position  of  the  stomach  is  ob- 
lique in  two  respects;  it  inclines  in  a small  degree  from 
above  downwards,  from  the  left  to  the  right;  and  it  also 
inclines  downwards  and  forwards,  from  behind.  Its  two 
orifices  are  situated  obliquely  with  respect  to  each  other; 
for,  if  the  stomach,  when  placed  with  its  small  curvature 
upwards,  were  divided  into  two  equal  parts  by  a vertical 
plane  passing  lengthways  through  it,  they  would  be  found 
on  different  sides  of  the  plane. 

As  the  oesophagus  terminates  in  the  stomach  immedi- 
ately after  it  has  passed  through  an  aperture  of  the  dia- 
phragm, it  is  evident  that  the  stomach  must  be  somewhat 
fixed  at  that  place;  but  it  is  more  moveable  at  its  other 
orifice;  for  the  extremity  of  the  duodenum,  into  which  it 
is  continued,  is  moveable. 

The  stomach  is  connected  to  the  concave  surface  of 
the  liver  by  the  reflexion  or  continuation  of  the  peritone- 
um, which  forms  the  lesser  omentum.  This  membrane, 
after  extending  over  each  surface  of  the  stomach,  con- 
tinues from  its  great  curve  in  the  form  of  the  large  omen- 
tum, and  connects  it  to  different  parts,  especially  to  the 
colon.  There  are  likewise  folds  of  the  peritoneum,  as  it 
passes  from  the  diaphragm  and  from  the  spleen  to  the 
stomach,  which  appear  like  ligaments. 

Notwithstanding  these  various  connections,  the  sto- 
mach undergoes  considerable  changes  in  its  position. 


97 


External  Coat  of  the  Stomach. 

When  it  is  nearly  empty,  and  the  intestines  are  in  the 
same  situation,  its  broad  surfaces  are  presented  forwards 
and  backwards;  but  when  it  is  distended,  these  surfaces 
are  presented  obliquely  upwards  and  downwards,  and  the 
great  curvature  forwards.  When  its  anterior  surface  is 
presented  upwards,  its  orifices  are  considerably  influenced 
in  their  direction,  and  the  oesophagus  forms  an  angle  with 
the  plane  of  the  stomach. 

The  stomach  is  composed  of  four  dissimilar  laminae, 
which  may  be  demonstrated  by  a simple  process  of  dis- 
section. 

There  is  first  a coat  or  external  covering  continued 
from  the  peritoneum:  within  this,  and  connected  to  it  by 
delicate  cellular  substance,  is  a coat  or  stratum  of  mus- 
cular fibres:  contiguous  to  these  fibres,  internally,  is  a 
layer  of  dense  cellular  substance,  called  a nervous  coat; 
and  last  is  the  internal  coat  of  the  stomach,  called  villous, 
or  fungous,  from  the  structure  of  its  surface. 

The  external  or  first  coat  of  the  stomach,  as  has  been 
already  stated,  is  continued  from  the  concave  surface  of 
the  liver  to  the  lesser  curve  of  the  stomach  in  two  deli- 
cate laminse,  which  separate  when  they  approach  the  sto- 
mach, and  pass  down,  one  on  each  side  of  it,  adhering 
firmly  to  it  in  their  course:  at  the  opposite  curve  of  the 
stomach  they  again  unite  to  form  the  great  omentum. 
The  stomach  is  therefore  closely  invested  by  the  perito- 
neum on  every  part  of  its  surface  except  two  strips,  one 
at  the  lesser  and  the  other  at  the  greater  curvature.  These 
strips  or  uncovered  places  are  formed  by  the  separation 
of  the  lamina:  above  mentioned,  which  includes  a trian- 
gular space  bounded  by  the  stomach  and  these  two  la- 
minae. In  these  triangular  spaces,  at  each  curvature  of 
the  stomach,  are  situated  the  bloodvessels  which  run 
along  the  stomach  in  those  directions,  and  also  the  glands 
which  belong  to  the  absorbent  vessels  of  this  viscusP 
The  peculiar  arrangement  of  the  lamina  at  this  place  i§ 
¥01..  II.  N 


98  Muscular  and  Nervous  Coats  of  the  Stomach. 

particularly  calculated  to  permit  the  dilatation  of  the  sto- 
mach. When  it  is  dilated  the  laminae  are  in  close  contact 
with  its  surface,  and  the  bloodvessels  being  in  the  angle 
formed  by  the  adhesion  of  the  two  laminae  to  each  other, 
are  so  likewise:  when  it  contracts,  the  bloodvessels  ap- 
pear to  recede  from  it,  and  the  laminae  are  then  applied  to 
each  other. 

Where  the  peritoneum  thus  forms  a coat  to  the  sto- 
mach, it  is  stronger  and  thicker  than  it  is  between  the 
liver  and  stomach.  In  a recent  subject  it  is  very  smooth 
and  moist,  but  so  thin  that  the  muscular  fibres,  bloodves- 
sels, &c.  appear  through  it.  If  it  is  carefully  dissected 
from  the  muscular  coat,  it  appears  somewhat  flocculent 
on  that  surface  which  adhered  to  the  frtuscular  fibres.  It 
seems  to  be  most  abundantly  furnished  with  serous  ves- 
sels; but  it  has  been  asserted  by  Mascagni  and  Soemmer- 
ing, that  a large  proportion  of  its  texture  consists  of  ab- 
sorbent vessels.  The  cellular  substance  which  connects 
this  to  the  muscular  coat  appears  no  way  different  from 
ordinary  cellular  membrane. 

The  Muscular  Coat  of  the  stomach  has  been  described 
very  differently  by  respectable  anatomists;  some  consider- 
ing it  as  forming  three  strata  of  fibres,  and  others  but  two. 
If  the  stomach  and  a portion  of  the  oesophagus  attached  to 
it  be  moderately  distended  with  air,  and  the  external  coat 
carefully  dissected  away,  many  longitudinal  fibres  will 
appear  on  every  part  of  it,  that  evidently  proceed  from  the 
oesophagus:  these  fibres  are  particularly  numerous  and 
strong  on  the  lesser  curvature  of  the  stomach.  Beside  the 
longitudinal  fibres  there  are  many  that  have  a circular  di- 
rection, and  these  are  particularly  numerous  towards  the 
small  extremity;  but  it  has  been  doubted  whether  there 
are  any  fibres  in  the  muscular  coat  of  the  stomach  that  go 
directly  round  it.  The  whole  surface  of  the  stomach,  when 
the  peritoneal  coat  is  removed,  appears  at  first  view  to  be 
uniformly  covered  by  muscular  fibres;  but  upon  close  ex- 


99 


Internal  Coat  of  the  Stomach. 

animation  there  are  interstices  perceived,  which  are  occu- 
pied with  firm  cellular  membrane. 

In  contact  with  the  internal  surface  of  the  muscular 
coat  is  the  cellular  stratum , which  has  been  called  the 
Nervous  Coat  of  the  stomach.  It  is  dense  and  firm,  of  a 
whitish  colour,  resembling  condensed  cellular  membrane. 
It  was  considered  as  different  from  ordinary  cellular 
membrane;  but  if  air  be  insinuated  into  its  texture,  by 
blowing  between  the  muscular  and  villous  coats,  while  it 
connects  them  to  each  other,  it  exhibits  the  proper  ap- 
pearance of  cellular  substance.  It  however  adds  greatly  to 
the  general  strength  of  the  stomach,  and  the  vessels  which 
terminate  in  the  villous  coat  ramify  in  it. 

The  internal  coat  of  the  stomach  in  the  dead  subject  is 
commonly  of  a whitish  colour,  with  a tinge  of  red.  It  is 
named  villous,  from  its  supposed  resemblance  to  the  sur- 
face of  velvet.  It  has  also  been  called  fungous,  because  the 
processes  analogous  to  the  villi  are  extremely  short,  and 
its  surface  has  a granulated  appearance;  differing  in  these 
respects  from  the  internal  surface  of  the  intestines.  It  is 
continued  from  the  lining  membrane  of  the  oesophagus, 
but  is  very  different  in  its  structure.  Many  very  small 
vessels  seem  to  enter  into  its  texture,  which  are  derived 
from  branches  that  ramify  in  the  nervous  coat.  It  is  sup- 
posed by  several  anatomists  of  the  highest  authority,  to 
have  a cuticle  or  epithelium;  and  it  said  that  such  a 
membrane  has  been  separated  by  disease.  It  ought  how- 
ever, to  be  remembered,  that  the  structure  of  the  villous 
coat  of  the  stomach  and  intestines,  is  essentially  different 
from  the  structure  of  the  cuticle. 

The  internal  coat  of  the  stomach  is  generally  found  co- 
vered, or  spread  over,  with  mucus,  which  can  be  readily 
scraped  off.  This  mucus  is  certainly  effused  upon  it  by 
secreting  organs,  and  it  has  been  supposed  that  there  were 
small  glandular  bodies  exterior  to  the  villous  coat,  which 
furnished  this  secretion;  but  the  existence  of  such  bodies 


'100 


Gastric  Liquor. 


is  very  doubtful,  as  many  skilful  anatomists  have  not  met 
with  any  appearance  that  could  be  taken  for  glands,  except 
in  a very  few  instances,  which  would  not  be  the  case  if 
those  appearances  had  been  natural.  Pores,  perhaps  the 
Orifices  of  mucous  follicles,  and  also  of  exllalent  vessels, 
are  very  numerous;  but  no  proper  glandular  masses  are 
attached  to  them.  Glands,  as  have  been  already  said,  are 
found  in  the  triangular  spaces  between  the  laminae  of  the 
peritoneum  at  the  great  and  small  curvatures  of  the  sto- 
mach, but  these  evidently  belong  to  the  absorbent  system. 
Besides  the  mucus  above  mentioned,  a large  quantity  of  a 
different  liquor,  the  proper  Gastric  Juice,  or  fluid  of  the 
stomach,  is  effused  from  its  surface.  It  has  been  supposed 
that  this  fluid  is  furnished  by  the  small  glandular  bodies 
believed  to  exist  between  the  coats  of  this  organ;  but,  ad- 
mitting the  existence  of  these  glands,  they  are  not  suffi- 
ciently numerous  to  produce  so  much  of  it  as  is  found, 
and  it  is  therefore  probable  that  this  fluid  is  discharged 
from  the  orifices  of  exhalent  vessels  in  the  internal  surface. 

Much  information  respecting  the  gastric  liquor  has 
been  obtained  within  a few  years  past  by  the  researches 
of  physiologists,  and  they  are  generally  agreed  that  it  is 
the  principal  agent  in  the  effects  produced  by  the  sto- 
mach upon  alimentary  substances.* 

* On  this  subject  the  student  may  consult  with  advantage, 

M.  Reaumur.  In  the  Memoirs  of  the  Academy  of  Sciences  for 
1752. 

John  Hunter.  London  Philosophical  Transactions  for  1772;  and 
also  his  observations  on  the  Animal  Economy,  1786. 

Dr.  Edward  Stevens.  Inaugural  Thesis  de  Alimentorum  Con- 
coctione.  Edinburgh,  1777. 

The  Abbe  Spalanzani.  Dissertations  relative  to  Natural  History,  &c. 
The  first  volume  of  the  English  translation  contains  the  author’s 
dissertations  on  digestion,  and  also  the  first  paper  of  Mr.  Hunter, 
and  the  Thesis  of  l)r.  Stevens,  as  well  as  an  account  of  the  experi- 
ments of  Mr.  Gosse  of  Geneva. 

In  addition  to  these,  there  are  several  interesting  essays  in  the 


101 


The  Pylorus. 

As  the  muscular  coat  of  the  stomach  frequently  varies 
its  dimensions,  the  villous  artd  nervous  coats,  which  have 
no  such  power  of  contraction,  cannot  exactly  fit  it.  They 
therefore  generally  appear  larger,  and  of  course  are 
thrown  into  folds  or  rugae.  These  folds  are  commonly  in 
a longitudinal  direction;  but  at  the  orifices  of  the  sto- 
mach they  are  arranged  in  a radiated  manner,  and  some- 
times they  are  observed  in  a transverse  direction.  They 
depend  upon  the  contraction  of  the  muscular  fibres,  and 
disappear  entirely  when  the  stomach  is  laid  open  and 
spread  out. 

At  the  lower  orifice  is  a circular  fold,  which  is  perma- 
nent, and  constitutes  the  valve  denominated  Pylorus.  It 
appears  like  a circular  septum  with  a large  foramen  in  its 
center,  or  like  a flat  ring.  The  villous  and  nervous  coats 
of  the  stomach  contribute  to  this,  merely  by  forming  the 
circular  fold  or  ruga;  and  within  this  fold  is  a ring  of 
muscular  fibres,  evidently  connected  with  the  circular 
fibres  of  the  muscular  coat  of  the  stomach,  the  diameter 
of  which  at  this  place  is  not  larger  than  that  of  an  intes- 
tine: the  fibres  of  this  ring  seem  a part  of  the  muscular 
coat  projecting  into  the  cavity  of  the  stomach  and  duo- 
denum. If  a portion  of  the  lesser  extremity  of  the  sto- 
mach and  the  adjoining  part  of  the  duodenum  be  detach- 
ed, and  laid  open  by  a longitudinal  incision,  and  then 
spread  out  upon  a board,  the  internal  coat  can  be  very 
easily  dissected  from  the  muscular,  and  the  pylorus  will 
then  appear  like  a ridge  or  narrow  bundle  of  muscular 
fibres,  which  runs  across  the  extended  muscular  mem- 
brane. It  is  evident  that  when  the  parts  are  replaced  so 
as  to  form  a cylinder,  this  narrow  faciculus  will  form  a 
ring  in  it.  Thus  arranged,  the  circular  fibres  can  readily 
close  the  lower  orifice  of  the  stomach. 

French,  German,  and  Italian  languages,  a compilation  of  which  is 
to  be  found  in  Johnson’s  “ History  of  the  progress  and  present  state 
of  Animal  Chemistry.”  See  Vol.  I.  page  180. 


102  Lymphatics  and  Nerves  of  the  Stomach. 

The  pylorus  separates  the  stomach  from  the  intestine 
duodenum;  and  this  separation  is  marked  exteriorly  by  a 
small  circular  depression,  which  corresponds  exactly 
with  the  situation  of  the  pylorus. 

The  arteries  of  the  stomach  are  derived  from  the 
Coeliac,  the  first  branch  which  the  aorta  sends  off  to  the 
viscera  of  the  abdomen.  This  great  artery,  immediately 
after  it  leaves  the  aorta,  is  divided  into  three  branches, 
which  are  distributed  to  the  stomach,  the  liver,  and  the 
spleen,  and  are  called  the  Superior  Coronary  or  Gastric, 
the  Hepatic , and  the  Splenic.  Besides  the  first  mentioned 
branch,  which  is  distributed  principally  to  the  neigh- 
bourhood of  the  cardia  and  to  the  lesser  curvature,  the 
stomach  receives  a ‘considerable  branch  from  the  hepatic, 
which  passes  along  the  right  portion  of  its  great  curva- 
ture, and  has  been  called  the  right  gastro-epiploic,  and 
another  from  the  spleen,  which  passes  along  the  left  por- 
tion of  the  great  curvature,  and  has  been  called  the  left 
gastro-epiploic.  In  addition  to  these  branches,  the  splenic 
artery,  before  it  enters  the  spleen,  sends  off  several  small 
arteries  to  the  great  extremity  of  the  stomach,  which  are 
called  vasa  brevia. 

These  vasa  brevia  generally  arise  from  the  main  trunk 
of  the  splenic  artery,  but  sometimes  from  its  branches. 

The  veins  which  receive  the  blood  from  these  arteries 
have  similar  names,  and  pursue  corresponding  courses 
backwards;  but  they  terminate  in  the  vena  portarum. 

The  absorbent  vessels  of  the  stomach  are  very  numer- 
ous and  large:  they  pass  to  the  glands  which  are  on  the 
two  curvatures,  and  from  thence  to  the  thoracic  duct.  It 
is  an  important  fact  relative  to  the  history  of  digestion, 
that  there  are  good  reasons  for  doubting  whether  chyle 
commonly  passes  through  them,  notwithstanding  their 
number  and  size.* 

* Sabatier,  however,  in  one  subject  observed  white  lines  on  the 
stomach,  which  he  suspected  to  be  lacteals.  See  his  account  of  the 
absorbents  of  the  stomach. 


103 


The  Intestines  in  general. 

The  nerves  of  the  stomach  are  derived  principally 
from  the  two  great  branches  of  the  par  vagum,  which 
accompany  the  oesophagus  and  are  mostly  spent  upon 
this  organ.  It  also  receives  branches  from  several  plex- 
uses, which  are  derived  horn  the  splanchnic  portions  of 
the  intercostal  nerves. 


SECTION  III. 

Of  the  Intestines. 

THE  intestines  form  a continued  canal  from  the  py- 
lorus to  the  anus,  which  is  generally  six  times  the  length 
of  the  subject  to  which  they  belong.  Although  the  diffe- 
rent parts  of  this  tube  appear  somewhat  different  from 
each  other,  they  agree  in  their  general  structure.  The 
coats  or  laminas  of  which  they  are  composed  are  much 
like  those  of  the  stomach,  but  the  peritoneum  which 
forms  the  ir  external  coat  does  not  approach  them  in  the 
same  manner;  nor  is  it  continued  in  the  form  of  omen- 
tum from  the  whole  tube,  there  being  only  a certain  por- 
tion of  intestine,  viz.  the  colon,  from  which  such  a pro- 
cess of  peritoneum  is  continued. 

The  Muscular  Coat,  like  that  of  the  stomach,  consists 
of  two  strata,  the  exterior  of  which  is  composed  of  lon- 
gitudinal fibres,  which  adhere  to  the  external  coat,  and 
do  not  appear  very  strong.  The  other  stratum,  consist- 
ing of  circular  or  transverse  fibres,  is  stronger,  as  the 
fibres  are  more  numerous.  It  is  observable  that  they  ad- 
here to  the  longitudinal  fibres:  and  they  seldom  if  ever 
form  complete  circles. 

The  cellular  substance  immediately  within  the  mus- 
cular fibres  resembles  the  nervous  coat- of  the  stomach 
in  its  firmness  and  density.  It  is  likewise  so  arranged 


104 


Villous  Coat  of  the  Intestines. 

as  to  form  many  circular  ridges  on  its  internal  surface, 
which  support  to  a certain  degree  the  permanent  circu- 
lar plaits  of  the  internal  coat,  called  valvulas  conniventes. 

The  inner  surface  of  the  internal  coat  has  been  com- 
monly compared  to  that  of  velvet,  and  the  coat  is  there- 
fore called  villous;  but  there  is  certainly  a considerable 
difference  between  these  surfaces;  for  if  a portion  of  the 
small  intestine  be  inverted,  and  then  suspended  in  per- 
fectly transparent  water,  in  a clear  glass,  and  examined 
with  a strong  light,  it  will  appear  like  the  external  sur- 
face of  the  skin  of  a peach,  on  which  the  down  or  hair- 
like processes  are  not  so  close  as  those  on  velvet.  On 
this  surface,  between  the  villi,  there  are  many  orifices  of 
mucous  follicles  and  of  exhaling  vessels.*  Exterior  to 
the  villous  coat,  many  very  small  glandular  bodies  are 
sometimes  found,  which  are  called  after  their  describers 
Glandulae  Brunneri  and  Peyeri. 

The  internal  coat  of  the  upper  portion  of  the  intestinal 
tube  is  arranged  so  as  to  form  a great  number  of  trans- 
verse or  circular  folds  or  plaits,  called  Valvula  Conni- 
ventes',  which  do  not  generally  extend  round  the  intes- 
tine, but  are  segments  of  circles;  they  are  so  near  each 
other  that  their  internal  edges,  which  are  very  moveable, 
may  be  laid  upon  the  folds  next  to  them,  like  tiles  or 
shingles.  It  is  evident  that  this  arrangement  of  the  in- 
ternal coat  must  add  greatly  to  its  length.  This  coat  is 
extremely  vascular,  so  that  in  the  dead  subject  it  can  be 
uniformly  coloured  by  a successful  injection.  The  minute 
structure  of  it  has  been  the  subject  of  very  diligent 
inquiry.  There  can  be  no  doubt  but  that  an  immense 

* It  appears  clearly,  from  the  account  of  Lieberkuhn,  that  the  ori- 
fices or  terminations  of  the  arteries  on  the  intestines,  are  distinct  from 
the  follicles;  for  he  forced  injection  from  the  arteries  into  the  cavity 
of  the  intestines,  and  found  the  follicles  still  filled  with  mucus.  He 
then  urged  the  injection  further,  and  filled  the  follicles,,  or  forced 
fhe  mucus  out  of  them. 


Lieberkuhn  on  the  Villous  Coat.  105 

number  of  exhaling  and  of  absorbent  vessels  open  upon 
it;  but  there  are  many  different  opinions  respecting  the 
termination  of  one  set  of  vessels  and  the  commencement 
of  the  other. 

A very  interesting  account  of  the  Villous  Coat  was 
published  in  1744,  by  Lieberkuhn,  who  was  consider- 
ed by  his  cotemporaries  as  a most  expert  practical  ana-  ^ 
tomist,  and  was  also  very  skilful  in  microscopical  ex- 
aminations, for  which  he  was  particularly  calculated,  as 
his  natural  powers  of  vision  were  uncommonly  strong. 

In  his  essay  he  refers  to  his  preparations,  which  were  at 
Berlin,  and  which  appear  to  have  excited  great  surprise 
in  the  minds  of  the  members  of  the  Academy  of 
Sciences  of  Prussia,  at  a time  when  one  of  the  first  an- 
atomists of  Europe,  the  celebrated  Meckel,  was  of  their 
number. 

According  to  this  account,  the  internal  surface  of  the 
small  intestines  abound  with  villi,  and  with  the  orifices 
of  follicles.  These  villi  are  about  the  fifth  part  of  a line 
in'  breadth.  In  each  of  them  is  a cavity  filled  wfith  a soft 
spongy  substance,  which  has  one  or  more  orifices  com- 
municating with  the  intestines,  and  from  which  also  pro- 
ceeds a lacteal  vessel.  On  the  membrane  which  forms 
this  cavity,  bloodvessels  are  most  minutely  ramified. 
This  cavity  he  calls  an  ampullula,  and  supposes  it  to 
constitute  the  principal  part  of  the  villus.  By  injecting 
the  arteries  of  the  intestine,  he  was  able  to  pass  a fluid 
through  the  ampullula  into  the  cavity  of  the  gut;  he  kept 
a stream  of  air  in  this  way  passing  through  the  ampullula 
until  it  was  nearly  dry  and  stiff,  and  then  laid  it  open  with 
a fine  instrument.  From  the  appearances  which  then  pre- 
sented, he  inferred  that  the  cavity  of  the  ampullula  was 
occupied  with  a spongy  or  cellular  substance.  Around 
each  villus  he  found  a number  of  mucous  follicles,  which 
often  were  filled  with  a tenacious  mucus:  and  distinct 
from  these  must  be  the  exhalent  orifices,  which  dis- 
Vol.  II.  O 


106  Hewson  and  others  on  the  Villi. 

charged  a fluid  injected  by  the  arteries  without  passing 
through  the  mucous  follicles. 

Lieberkuhn  died  early,  and  left  but  one  essay  on  this 
subject,  which  was  originally  published  in  Holland,  in 
1744,  but  has  been  republished  by  the  Academy  of  Ber- 
lin, in  their  Memoirs;  and  also  by  Mr.  John  Sheldon,  of 
London. 

This  account  of  Lieberkuhn  appears  to  have  been  ad- 
mitted by  Haller;  but  it  has  been  rigidly  scrutinized  by 
some  of  the  anatomists  of  London,  who  were  particularly 
interested  with  the  subject;  as  they  had  paid  great  atten- 
tion to  the  absorbent  system,  and  were  very  successful  in 
the  investigation  of  it. 

The  late  Mr.  Hewson,  whose  opinion  is  entitled  to  the 
greatest  respect,  rejected  the  idea  of  the  ampullula,  and  be- 
lieved that  the  villi  are  composed  of  networks  of  lacteals, 
as  well  as  arteries  and  veins;  although  he  added  that 
“ this  is  the  only  circumstance  concerning  these  parts 
in  which  he  should  differ  from  this  very  acute  observer.”* 

Mr.  Sheldon  agrees  with  Lieberkuhn:  but  Mr.  Cruik- 
shanks  asserts,  that,  “ in  some  hundred  villi,  he  has  seen 
the  lacteals  originate  by  radiated  branches,  whose  orifices 
were  distinct,  on  the  surface  of  the  villus.”  The  villus 
being  transparent,  when  the  intestine  was  immersed  in 
water,  these  branches,  filled  with  chyle,  could  be  seen 
passing  into  the  lacteal.  Mr.  Cruikshanks  therefore  sup- 
poses that  Lieberkuhn  was  mistaken,  and  that  the  spongy 
cavity,  or  ampullula,  was  the  common  cellular  membrane, 
connecting  together  all  the  arteries,  veins,  nerves,  and 
lacteals. 

It  seems  probable,  from  Mr.  Cruikshanks’  statement, 
that  Dr.  William  Hunter  held  the  same  opinion  with  him- 
self. And  there  is  also  reason  to  believe  that  Monro  the 


* See  Hewson’s  Experimental  Inquiries,  vol.  2,  page  171. 


Fyfe  and  others  on  the  Villi.  1,07 

second,  who  studied  anatomy  at  Berlin,  held  a different 
opinion  from  Lieberkuhn. 

Mr.  Fyfe,  who  has  heen  much  employed  in  the  inves- 
tigation of  the  absorbent  system,  and  must  be  perfectly 
acquainted  with  the  preparations  of  Monro,  asserts  that 
each  lacteal  takes  its  rise  upon  one  of  the  villi  by  numer- 
ous short  radiated  branches,  and  each  branch  is  furnished 
with  an  orifice  for  imbibing  chyle. 

Several  of  the  late  French  writers  adopt  the  opinion  of 
Lieberkuhn;  but  his  countryman  Soemmering  gives  a 
different  account  of  the  subject.  He  says,  that,  besides  the 
bloodvessels,  each  villus  consists  of  a fine  network  of  ab- 
sorbent vessels,  whose  orifices  may  be  distinctly  recog- 
nized; and  that  from  six  to  ten  of  these  orifices  are  some- 
times discovered. 

Mascagni,  who  has  published  the  most  extensive  work 
upon  the  absorbent  system  that  has  yet  appeared,  sup- 
poses Lieberkuhn  to  have  been  mistaken,  and  confirms  the 
description  of  Hewson:  but  he  also  agrees  with  Hewson 
in  his  opinion  of  the  general  accuracy  of  Lieberkuhn. 

Notwithstanding  their  differences  respecting  the  origin 
of  the  lacteals,  all  these  observers  have  agreed,  that  the 
orifices  which  communicate  with  the  lacteals  are  on  the 
villi;  and  that  these  villi  contain  also  very  fine  ramifica- 
tions of  bloodvessels.  They  have  also  agreed,  that  the 
surface  of  the  intestine  in  the  intervals  of  the  villi  seems 
occupied  with  the  orifices  of  ducts  or  of  exhalent  ves- 
sels, * 

* On  this  subject  the  student  will  consult,  with  advantage,  Hewson’s 
Experimental  Inquiries,  vol.  2d;  Sheldon’s  history  of  the  Absorbent 
System,  part  1st;  Cruikshanks  on  the  Anatomy  of  the  Absorbing  Ves- 
sels; and  the  Historia  Vasorum  Lymphaticorum  Corporis  Humani, 
©f  Mascagni. 


108 


Division  of  the  Intestines. 

Although  there  is  a considerable  degree  of  uniformity 
in  the  structure  of  the  intestinal  canal,  different  parts  of 
it  are  very  distinguishable  from  each  other  by  their  exte- 
rior appearance,  by  their  size,  their  investments,  and  their 
position. 

The  first  division  is  into  two  great  portions,  whiqh 
are  very  different  from  each  other  in  their  diameter  and 
length,  as  well  as  their  situation:  the  first  portion  being 
much  smaller  in  diameter,  and  near  four  times  the  length 
of  the  other. 

These  portion*  are  therefore  known  by  the  names  of 
Great  and  Small  Intestines , and  the  line  of  separation  be- 
tween them  is  very  strongly  marked;  for  they  do  not  gra- 
dually change  into  each  other,  but  the  alteration  in  size 
and  in  exterior  appearance  is*  very  abrupt,  and  their  com- 
munication is  not  perfectly  direct.  A considerable  portion 
of  the  Great  Intestine  is  fixed  immoveably  in  the  abdo- 
men, while  a large  part  of  the  Small  Intestine  is  very 
moveable. 

Each  of  these  great  portions  of  the  intestinal  tube  is 
subdivided  into  three  parts.  Thus,  in  the  Small  Intestine , 
there  is  a piece  at  the  commencement  called  Duodenum , 
a great  part  of  which  has  no  coat  from  the  peritoneum, 
and  is  immoveably  fixed  in  one  situation;  while  all  the 
remainder  of  the  smail  intestine  has  a uniform  covering 
from  the  peritoneum,  and  is  very  moveable.  This  last 
piece,  notwithstanding  its  exterior  uniformity,  is  consi- 
dered as  forming  two  parts.  The  uppermost  two  fifths 
form  one  part,  which  is  called  Jejunum;  and  the  remain- 
der is  called  Ileon.  The  Great  Intestine  commences  in 
the  lower  part  of  the  right  side  of  the  abdomen,  and 
after  proceeding  up  that  side  crosses  over  to  the  left,  along 
which  it  descends  to  the  lower  part  again,  when  by  a pe- 
culiar flexure  it  proceeds  to  the  center  of  the  posterior 


109 


Commencement  of  the  Small  Intestines. 

margin  of  the  pelvis,  from  which  it  passes  down  to  the 
anus.  A short  portion  of  this  intestine,  which  is  above  its 
junction  with  the  ileon,  is  called  Ccecum;  the  part  which 
proceeds  from  this,  round  the  abdomen,  is  called  Colon; 
and  the  portion  which  is  in  the  pelvis  is  called  Rectum. 


Of  the  Small  Intestines. 

Previous  to  the  description  of  the  small  intestines,  it  is 
necessary  to  observe,  that  the  Mesocolon , or  process  of  the 
peritoneum  connected  to  the  transverse  portion  of  the  co- 
lon, forms  a kind  of  moveable  and  incomplete  septum, 
which  divides  the  abdomen  into  an  upper  and  lower 
apartment.  Above  this  septum  are  the  stomach,  with  the 
commencement  of  the  duodenum,  the  liver,  and  the  spleen; 
below  it,  that  portion  of  the  small  intestine  which  is  called 
jejunum  and  ileon,  makes  its  appearance.  The  portion  of 
the  intestine  which  passes  from  the  stomach  to  the  jeju- 
num, and  is  called  Duodenum , is  so  much  involved  by  the 
mesocolon,  that  the  greatest  part  of  it  cannot  be  seen  with- 
out dissecting  the  mesocolon  from  its  connection  with  the 
back  of  the  abdomen.  For  the  duodenum  proceeds  back- 
wards from  the  pylorus,  and  passing  down  behind  the  pe- 
ritoneum, enters  a vacant  space  between  the  two  laminas 
of  the  mesocolon;  it  proceeds  for  some  distance  in  this 
space,  and  then  emerges  on  the  lower  side  of  the  meso- 
colon. Here  the  duodenum  terminates,  and  the  small  in- 
testine then  is  invested  by  the  peritoneum  in  such  manner 
as  to  form  mesentery,  which  continues  with  it  throughout 
its  whole  course  to  the  great  intestine.  This  portion  of  the 
intestine,  although  very  uniform  in  its  exterior  appear- 
ance, as  has  been  observed  before,  is  divided  into  Jeju- 
num and  Ileon:  the  Jejunum  being  the  upper  portion,  which 
begins  at  the  mesocolon;  and  the  Ileon  the  lower  portion, 
which  opens  into  the  great  intestine.  • 


110 


Situation  of  the  Duodenum. 


Of  the  Duodenum. 

The  length  of  this  intestine  is  equal  to  the  breadth  of 
twelve  fingers,  and  hence  its  name.  It  is  very  different 
from  the  rest  of  the  small  intestine,  not  only  as  respects  its 
position,  and  investment  by  the  peritoneum;  but  on  ac- 
count of  its  connexion  with  the  liver  and  pancreas,  by 
means  of  their  excretory  ducts,  which  open  into  it.  From 
this  connexion  with  these  glands,  probably,  all  the  pecu- 
liarities of  its  position  are  to  be  deduced. 

When  the  stomach  is  in  its  natural  situation,  the  pylo- 
rus is  at  some  distance  from  the  back  of  the  abdomen. 
The  duodenum  proceeds  backwards  from  this  point,  and 
passes  near  the  neck  of  the  gall-bladder,  being  here  con- 
nected with  the  small  omentum;  it  then  curves  downwards, 
and  descends  belore  the  right  kidney,  sometimes  as  low  as 
the  lower  part  of  it;  then  it  curves  again,  and  passes  over 
to  the  left:  after  it  has  arrived  at  the  left  side  of  the  spine,  at 
the  second  or  third  lumbar  vertebra,  it  projects  forwards 
and  downwards  to  form  the  jejunum.  The  only  portion 
of  this  intestine  which  is  moveable,  is  that  which  is  in  sight 
as  it  proceeds  immediately  from  the  duodenum,  being 
about  an  inch  and  a half,  or  two  inches  in  length.  The  re- 
mainder is  connected  to  the  back  of  the  abdomen,  and  lies 
between  the  two  laminae  of  the  mesocolon.  In  its  progress 
it  passes  before  the  aorta  and  the  vena  cava,  but  the  princi- 
pal branch  of  the  vena  portarum  is  before  it. 

The  duodenum  is  larger  in  diameter  than  any  other 
part  of  the  small  intestines,  and  has  a stronger  muscular 
coat.  Its  general  situation  admits  of  great  dilatation,  and  it 
has  been  called  a second  stomach.  Its  internal  coat  is 
strictly  villous,  in  the  anatomical  sense  of  the  word;  and 
its  folds,  the  valvulae  conniventes,  begin  at  a small  distance 
from  the  pylorus.  The  orifices  of  many  mucous  ducts  are 
to  be  seen  on  its  surface.  It  is  supposed  that  some  of  these 
are  the  terminations  of  ducts  from  the  glands  of  Brunner, 


Ill 


Jejunum  and  Ileon. 

which  sometimes  appear  in  the  villous  coat,  or  very  close 
to  it  exteriorly;  being  small  flat  bodies,  with  a depression 
in  the  center,  and  a foramen  in  the  depression.  They  are 
sometimes  very  numerous  at  the  upper  extremity  of  this 
intestine,  and  diminish  gradually  towards  the  other  extrei 
mity. 

The  biliary  and  pancreatic  ducts  open  posteriorly 
into  the  duodenum,  rather  above  the  middle  of  it.  The 
orifice  of  these  ducts  is  generally  surrounded  by  a small 
tubercle,  which  is  oblong,  somewhat  rounded  at  one  ex- 
tremity, and  pointed  at  the  other.  Sometimes  this  orifice 
is  in  a plait,  like  one  of  the  valvulas  conniventes.  Most 
commonly  the  two  ducts  unite  before  they  perforate  the 
coat,  so  as  to  form  but  one  orifice;  and  sometimes  they 
open  separately,  but  always  very  near  to  each  other. 

Absorbent  vessels,  which  contain  chyle,  are  found  on 
the  duodenum. 

The  Jejunum  and  Ileon 

Are  situated  in  the  abdomen  very  differently  from  the 
duodenum.  When  the  cavity  is  opened,  and  the  omentum 
raised,  they  are  in  full  view;  and  every  portion  of  them, 
except  the  two  extremities  and  the  parts  near  them,  can 
readily  be  moved.  This  freedom  of  motion  is  owing  to  the 
manner  in  which  they  are  invested  by  the  peritoneum;  or 
in  the  technical  language  of  anatomy,  to  the  length  of  their 
mesentery.  They  agree  in  their  structure  with  the  general 
description  of  the  small  intestines,  but  their  muscular  coat 
is  rather  weaker  than  that  of  the  duodenum.  The  valvulse 
conniventes  are  very  numerous  and  large  in  the  upper  part 
of  the  tube,  or  the  jejunum;  and  gradually  diminish  in 
number,  until  they  finally  disappear,  in  the  lower  part  of 
the  ileon.  The  villous  coat  is  in  perfection  in  the  jejunum, 
the  villi  being  more  conspicuous  here  than  in  any  other 
part  of  the  intestinal  tube.  There  are  frequently  found, 


1 12  Distinction  between  Jejunum  and  Ileon. 

exterior  to  this  coat,  but  intimately  connected  with  it, 
many  small  glandular  bodies  of  a roundish  form,  which 
are  often  clustered  together  at  that  part  of  the  intestine 
which  corresponds  with  the  interstice  of  the  laminae  of  the 
mesentery.  They  are  called  Peyer’s  glands,  after  the  anato- 
mist who  first  described  them;  and  are  supposed,  like 
the  glands  of  Brunner,  to  secrete  mucus.  If  a portion  of 
the  jejunum  be  inverted,  and  moderately  distended  with 
air,  these  bodies  appear  very  distinctly  in  it,  dispersed  at 
small  distances  from  each  other.  In  the  ileon  they  appear 
in  small  clusters,  which  often  have  the  appearance  of 
disease. 

No  natural  line  of  separation  for  distinguishing  the  je- 
junum and  ileon  from  each  other,  is  to  be  found;  but  these 
names  are  still  retained;  and  therefore  a rule  laid  down  by 
Winslow  is  generally  adopted,  viz.  to  name  the  first  two 
fifths  of  the  tube  jejunum,  and  the  remainder  ileon.  There 
are,  however,  some  important  differences  between  these 
portions  of  the  intestine. 

In  the  jejunum,  the  valvulae  conniventes  are  so  nume- 
rous, that  they  lie  in  contact  with  each  other,  as  shingles  on 
the  roof  of  a house;  in  the  ileon  they  gradually  diminish 
in  number,  and  finally  disappear.  In  the  jejunum  the  villi 
are  much  stronger  than  they  are  in  the  ileon. 

It  is  very  difficult  to  acquire  a precise  idea  of  the  ar- 
rangement of  this  part  of  the  intestinal  tube,  while  it  is  in 
the  abdomen,  especially  if  it  be  much  distended;  but  if  it 
be  separated  at  each  extremity  from  the  intestine  with 
which  it  is  connected,  and  the  mesentery  cut  off  from  the 
back  of  the  abdomen,  and  the  whole  then  spread  out  upon 
a flat  surface,  it  will  appear,  as  has  been  already  said,  that 
the  intestine  is  arranged  so  as  to  form  a semicircle  or  large 
curve;  the  concavity  of  which  is  opposite  to  the  back  of 
the  abdomen,  while  the  convexity  presents  forward.  It 
will  also  appear,  when  thus  placed  upon  a table,  that  the 
intestine,  while  connected  with  the  mesentery,  is  laid  into 


113 


Construction  of  the  Mesentery. 

many  folds.  It  has  been  supposed,  that  the  middle  portion 
of  the  mesentery,  and  the  intestine  connected  with  it,  is 
generally  in  the  umbilical  region;  and  the  two  portions  on 
the  sides  of  it  are  in  the  iliac  regions:  but  their  situation 
in  the  abdomen  varies  considerably  at  different  times. 
When  the  viscera  of  the  pelvis  are  empty,  a large  portion 
of  the  small  intestine  is  in  the  pelvis;  but  when  those  vis- 
cera are  filled,  the  intestine  is  in  the  general  cavity  of  the 
abdomen. 

The  Mesentery 

Is  a process  of  the  peritoneum,  which  is  formed  in  the 
manner  of  a plait  or  fold,  and  of  course  consists  of  two  la- 
minae. These  laminae  proceed  from  the  back  part  of  the 
abdomen,  and  are  so  near  to  each  other,  that  they  compose 
one  substantial  process;  having  cellular  and  adipose  sub- 
stance, bloodvessels  and  nerves,  with  absorbent  or  lacteal 
vessels  and  their  glands,  between  them. 

The  form  of  this  process,  when  it  is  separated  from 
the  back,  and  the  intestines  are  detached  from  it,  is  some- 
what semicircular:  that  portion  of  its  margin  or  edge 
which  corresponds  to  the  diameter  of  the  semicircle,  is 
connected  to  the  back  of  the  abdomen,  and  called  the  root 
of  the  mesentery;  the  edge,  which  is  the  circumference  of 
the  semicircle,  is  connected  with  the  intestine.  The  edge 
connected  with  the  back  of  the  abdomen  is  commonly 
about  five  or  six  inches  in  length:  the  semicircular  edge, 
instead  of  extending  fifteen  or  eighteen  inches,  the  ordi- 
nary proportion,  is  attached  to  a portion  of  intestine  some- 
times twenty -four  feet  in  length.  The  mesentery  on  ac- 
count of  this  great  difference  between  its  diameter  and 
circumference,  has  been  compared  to  the  ruffle  of  a shirt- 
sleeve; its  roots  being  taken  for  the  plaited  edge  of  the 
ruffle,  and  the  circumference  for  its  loose  edge.  But  the 
comparison  is  not  precisely  accurate;  for  the  mesentery  is 
VOL.  II.  P 


114 


Root  of  the  Mesentery. 

not  plaited  at  its  root,  but  perfectly  smooth,  and  free  from 
every  kind  of  fold.  It  begins  to  enlarge  towards  its  cir- 
cumference, and  enlarges  to  that  degree,  that  it  falls  into 
plaits  or  folds:  precisely  such  as  would  exist  in  a semicir- 
cular piece  of  membrane  about  six  inches  in  diameter,  if 
a number  of  simple  incisions,  of  about  an  inch  and  a half 
in  length,  were  made  in  a radiated  direction  from  its  cir- 
cumference, and  if  portions  like  a sextant  or  quadrant 
were  taken  from  a circular  membrane  three  inches  in 
diameter,  and  united  by  their  edges  to  these  incisions,  so 
that  their  circumference  might  be  continuous  with  the 
circumference  of  the  large  semicircular  piece.  In  this 
case,  the  portions  like  quadrants  or  sextants  would  as- 
sume a folded  position  like  the  edge  of  the  mesentery, 
while  the  middle  of  the  semicircular  piece  would  preserve 
its  regular  form  without  folds;  as  is  the  case  with  the  me- 
sentery at  some  distance  within  its  circumference.  By 
many  additions  of  this  kind,  the  circumference  of  a mem- 
brane, which  was  originally  a semicircle  of  five  or  six 
inches,  may  be  extended  so  as  to  exceed  greatly  that  of 
the  mesentery.  It  seems  of  course  impossible  to  form  an 
accurate  model  of  the  mesentery  with  a single  piece  of 
membrane  or  paper;  but  it  may  be  easily  made  with  clay, 
or  any  ductile  substance.  A model  of  this  kind  must  ne- 
cessarily be  folded  after  the  manner  of  the  mesentery;  and 
its  circumference,  like  the  mesentery,  would  appear  as  if 
formed  of  portions  of  the  circumference  of  smaller  circles 
united  to  each  other.* 

The  root  of  the  mesentery  commences  with  the  jeju- 
num on  the  lower  side  of  the  mesocolon,  at  the  left  of  the 
spine,  and  extends  downwards  near  to  the  right  iliac  re- 
gion; crossing  the  spine  obliquely.  When  it  is  examined 

* A model,  upon  the  plan  first  mentioned,  was  invented  by  Dr.  J. 
G.  Shippen.  It  has  been  proposed,  I believe  by  M.  Gavard,  to  make 
one  with  a single  piece  of  buckskin,  of  a semicircular  form,  by 
stretching  it  at  the  circumference. 


Appearance  of  the  Caecum  and  Colon.  115 

in  its  natural  situation,  the  peritoneum  is  found  continued 
from  the  back  of  the  abdomen  to  the  intestine;  it  then  sur- 
rounds the  intestine,  and  continues  from  it  to  the  back  of 
the  abdomen  again.  There  must  therefore  be  two  laminae 
of  peritoneum  in  the  mesentery,  and  there  must  be  a 
small  portion  of  intestine  answering  to  the  interstice  be- 
tween these  laminae,  which  is  not  covered  by  the  perito- 
neum. The  bloodvessels,  and  absorbents  or  lacteals,  pass 
most  commodiously  to  the  intestines  between  these  la- 
minae; for  they  are  connected  with  large  trunks  that  lie 
on  or  near  the  spine,  and  the  root  of  the  mesentery  com- 
mences there. 

The  glands  connected  with  the  lacteals  or  absorbents 
are  very  conspicuous  in  the  mesentery,  and  are  commonly 
called  mesenteric  glands.  They  are  of  different  sizes, 
from  more  than  half  an  inch  to  one  or  two  lines  in  diame- 
ter. They  are  very  numerous,  and  scattered  irregularly, 
but  are  seldom  observed  very  near  to  the  intestine.  They 
are  often  enlarged  in  consequence  of  disease,  especially 
in  children. 

The  nerves  of  the  small  intestines,  which  are  derived 
principally  from  the  superior  mesenteric  plexus,  are  also 
to  be  found  here. 

The  adipose  matter  between  the  laminae  of  the  mesen- 
tery is  very  often  in  a large  quantity,  but  varies  in  pro- 
portion to  the  general  quantity  of  adeps  in  the  subject. 


OF  THE  GREAT  INTESTINES. 

The  Caecum  and  Colon 

Are  very  different  from  the  small  intestines  in  many  re- 
spects. They  are  much  larger  in  diameter.  Their  exter- 
nal surface  is  marked  by  three  longitudinal  bands  of  a 
light  colour,  which  extend  the  greatest  part  of  their  length, 


3 


116 


Position  of  the  C cecum. 

and  are  placed  nearly  at  equal  distances  from  each  other* 
The  spaces  between  these  bands  are  marked  by  tranverse 
indentations,  which  pass  from  one  band  to  the  other  at 
short  but  unequal  distances.  At  these  indentations  the 
coats  of  the  intestine  are  pressed  inwards,  as  if  a fine 
thread  had  been  drawn  round  it  externally,  while  the 
spaces  between  them  are  full  and  tumid,  and  on  this  ac- 
count are  called  cells. 

The  great  intestine,  with  these  appearances,  begins,  as 
has  been  already  observed,  in  the  right  iliac  region,  by  a 
rounded  end  which  rests  on  the  fossa  or  concave  surface 
formed  by  the  costa  of  the  ileum;  from  this  it  is  continued 
upwards  in  the  right  lumbar  region,  anterior  to  the  kid- 
ney, until  it  arrives  near  the  liver,  when  it  forms  a curve, 
and  passes  directly  across  the  abdomen  to  the  left  side. 
In  this  course  it  approaches  so  near  to  the  under  side  of 
the  liver,  that  it  is  often  in  contact  with  it,  and  with  the 
gall-bladder,  which,  after  death,  tinges  it  with  a yellow 
colour.  On  the  left  side  it  passes  down  the  lumbar  region, 
before  the  kidney,  to  the  left  iliac  region;  here  it  is  curved 
so  as  to  resemble  the  Roman  letter  S,  inverted;  this  curve 
generally  carries  it  to  the  right  side  of  the  spine,  and  then 
brings  it  back  to  the  center  of  the  sacrum.  Here  the  in- 
testine changes  its  course,  and  passing  into  the  pelvis, 
continues  downward,  in  contact  with  the  sacrum  and  coc- 
cygis,  and  partaking  of  the  curvature  of  those  bones,  until 
it  terminates  at  the  anus,  where  it  is  connected  with  the 
sphincter  and  levator  ani  muscles. 

About  two  inches  from  the  commencement  of  the  great 
intestine  the  ileon  opens  into  it  laterally;  and  all  that  por- 
tion which  is  between  its  commencement  and  the  insertion 
of  the  ileon  is  termed  C cecum , or  the  blind  intestine:  that 
part  of  the  great  tube,  which  is  included  in  its  course 
from  the  insertion  of  the  ileon  to  the  posterior  part  of  the 
brim  of  the  pelvis,  is  called  Colon;  and  the  remainder,  or 


Structure  of  the  Colon.  117 

the  part  which  is  contained  in  the  pelvis,  is  termed  Rec- 
tum. 

The  Ccecum  is  nearly  as  wide  as  it  is  long;  it  is  fixed 
in  the  right  iliac  fossa  by  the  peritoneum,  which  invests 
it  so  that  the  great  body  of  the  intestine  projects  from  the 
surface  of  the  fossa  covered  by  the  peritoneum;  but  a 
portion  is  in  close  contact  with  the  surface,  and  connect- 
ed to  it  by  cellular  membrane.  Its  external  surface,  co- 
vered by  the  peritoneum,  is  marked  by  two  of  the  bands 
or  stripes  before  mentioned,  which  proceed  on  it  length- 
ways. These  bands  are  in  full  view,  but  the  third  band 
is  generally  on  that  part  of  the  intestine  which  rests  on 
the  iliac  fossa,  and  is  therefore  out  of  sight.  At  the  round- 
% ed  extremity  of  the  caecum,  situated  anteriorly  and  inter- 
nally, is  a small  process  resembling  an  earth-worm  in 
form  and  size:  this  is  therefore  called  Appendicula  Ver- 
miformis.  It  is  hollow,  and  communicates  with  the  cavity 
of  the  caecum  at  the  place  of  junction;  and  like  the  caecum, 
has  its  other  extremity  closed  up.  It  is  composed  of  the 
same  number  of  coats  and  has  the  same  structure  as  the 
great  intestine:  its  length  varies  from  two  to  four  inches. 

The  longitudinal  bands  above  mentioned  commence  at 
the  junction  of  this  appendix  with  the  caecum,  and  conti- 
nue throughout  the  extent  of  the  colon.  They  appear  to 
be  formed  by  some  of  the'longitudinal  fibres  of  the  mus- 
cular coat,  which  are  arranged  close  to  each  other.  These 
fibres  seem  to  be  shorter  than  the  coats  of  the  intestine, 
and  the  interior  coats  adhere  firmly  to  them.  Thus  are 
produced  the  indentations  and  cells;  for  if  the  bands  are 
divided  transversely,  the  indentations  disappear,  and  the 
surface  of  the  intestine  becomes  uniform.  One  of  these 
bands  is  covered  by  the  mesocolon. 

The  circular  or  transverse  fibres  of  the  muscular  coat 
of  the  ccecum  and  colon  are  very  delicate,  and  not  numer- 
ous. 

The  internal  coat  differs  materially  from  that  of  the 


118 


Valve  of  the  Colon. 

small  intestines,  although  at  first  view  they  seem  to  resem- 
ble each  other;  for  if  a portion  of  the  ileon  and  of  the 
colon  be  inverted  and  suspended  in  water,  no  villi  can  be 
seen  with  the  naked  eye  on  the  internal  coat  of  the  colon, 
while  those  of  the  ileon  are  very  visible.  The  glands  ex- 
terior to  this  coat  are  larger  than  those  on  the  small  in- 
testines. 

Instead  of  valvulae  conniventes,  are  the  ridges  made 
by  the  indentations  or  depressions  above  described,  which 
separate  the  incomplete  cells  from  each  other.  These 
ridges  differ  essentially  from  the  valvulae  conniventes, 
because  all  the  coats  of  the  intestine  are  concerned  in 
their  formation,  whereas  the  valvulae  conniventes  are 
formed  by  the  villous  coat  only;  they  also  project  into  the 
cavity  of  the  intestine,  while  the  valvulae  are  laid  on  its 
surface.  They  pass  only  from  one  longitudinal  band  to 
another,  and,  in  consequence  of  this,  the  cells  are  small, 
and  the  position  of  each  band  is  very  evident  when  the 
intestine  is  laid  open. 

The  communication  of  the  ileon  with  the  great  intestine 
has  been  already  stated  to  be  on  the  left  side  of  it,  about 
two  inches  from  its  commencement.  The  aperture  is  so 
constructed,  that  it  is  considered  as  a valve,  and  is  called 
the  Valve  of  Bauhin,  or  ofTulpius,  after  the  anatomists 
who  have  described  it.  The  appearance  of  the  aperture  is 
as  follows:  If  the  caecum,  with  a small  portion  of  the  ileon 
and  of  the  colon,  be  separated  from  the  other  intestines, 
and  kept  in  an  inflated  state  until  it  be  so  dry  as  to  pre- 
serve its  form  when  opened,  and  then  if  the  caecum  and 
colon  be  laid  open  opposite  to  the  aperture  of  the  ileon, 
a large,  transverse  ridge,  resembling  some  of  the  ridges  or 
folds  just  described,  will  be  seen  projecting  into  the  cavity 
of  the  intestine.  In  the  internal  edge  of  this  fold  is  a long 
slit  or  opening,  which  forms  the  communication  between 
the  two  intestines.  It  is  obvious  that  the  form  of  this  fold 
must  be  that  of  a crescent;  and  that  its  two  surfaces  with 


119 


Structure  of  the  Valve  of  the  Colon. 

the  slit  between  them,  must  have  the  appearance  of  two 
lips,  which  would  readily  permit  a fluid  or  substance  of 
soft  consistence  to  pass  from  the  ileon  into  the  great  in- 
testines, but  must  impede,  if  not  prevent,  its  passage  back; 
especially  if  the  large  intestines  were  distended,  as  then 
the  lips  would  be  pressed  against  each  other. 

When  the  peritoneal  coat  is  dissected  from  each  of  the 
intestines  at  their  place  of  junction,  and  this  structure  is 
then  examined  from  without , it  appears  as  if  a transverse 
or  half  circular  indentation  had  been  formed  by  the  villous 
coat  of  the  great  intestine,  and  that  the  internal  coat  of  the 
extremity  of  the  ileon  was  pressed  into  this  indentation, 
and  united  to  the  internal  coat  of  the  great  intestine  which 
formed  it;  while  there  was  a slit,  both  in  the  indentation 
and  in  the  end  of  the  ileon,  which  formed  a communica- 
tion between  the  cavity  of  the  great  intestine  and  the  ileon. 
The  longitudinal  fibres  of  both  intestines,  as  well  as  their 
external  coats,  seemed  to  be  united,  so  as  to  form  a com- 
mon cover  for  them;  while  the  circular  fibres  were  blend- 
ed in  the  two  portions  of  the  indentation  which  form  the 
lips  of  the  orifice. 

This  orifice  is,  of  course,  transverse  with  respect  to  the 
intestine.  It  has  been  observed,  that  there  was  a difference 
in  the  thickness  and  strength  of  the  two  lips  or  valves;  that 
the  lower  valve  was  the  strongest,  and  appeared  to  have 
the  largest  proportion  of  muscular  fibres  in  its  composi- 
tion. At  the  extremities  of  the  orifice,  and  near  each  end 
of  the  fold  or  ridge,  are  tendinous  fibres,  which  give 
strength  to  the  structure;  they  are  called  the  Retinacula 
of  Morgagni,  as  they  were  first  described  by  that  ana- 
tomist. 

There  is  great  reason  for  believing  that  this  valve  can- 
not prevent  the  retrograde  motion  of  the  contents  of  the 
intestines  in  all  cases;  for  in  some  instances  of  hernia  and 
of  colic,  matter  perfectly  stercoraceous  has  been  vomited, 
and  the  probable  inference  from  such  a state  of  the  eject- 


120 


Position  of  the  Rectum. 

ed  matter  is,  that  this  matter  has  been  in  the  large  intes- 
tines. It  is  also  said,  that  suppositories  and  enemata  have 
been  discharged  by  vomiting. 

On  the  right  and  left  sides  of  the  abdomen,  the  colon  is 
in  close  contact  with  the  posterior  surface  of  the  cavity. 
The  peritoneum,  which  covers  this  surface,  extends  over 
the  intestine  also,  and  thus  retains  it  in  its  position.  The 
great  arch  of  the  colon,  which  is  loose  and  moves  far 
from  the  back  of  the  abdomen,  is  invested  by  the  two 
laminae  of  the  omentum,  which,  after  surrounding  it, 
unite  again  and  form  mesocolon.  Connected  with  the 
exterior  surface  of  the  colon  are  many  processes,  com- 
posed of  adipose  membrane,  varying  in  length  from  half 
an  inch  to  an  inch  and  a half:  these  appear  to  be  of  the  na- 
ture of  the  omentum,  and  are  therefore  generally  deno- 
minated Appendices  Epiploica. 

The  Rectum. 

After  forming  the  sigmoid  flexure,  the  colon  termi- 
nates; and  the  rectum  begins  opposite  to  the  lower  sur- 
face of  the  last  lumbar  vertebra,  and  nearly  in  contact 
with  it:  from  this  it  proceeds  downwards,  forming  a curve 
like  the  sacrum,  until  it  terminates  at  the  anus,  where  it 
is  invested  with  the  muscles  called  the  sphincter  and  le- 
vator ani.  It  is  called  rectum,  because  in  this  course  it 
is  supposed  not  to  incline  to  either  side;  but  it  is  often 
found  on  one  side  of  the  middle  line.* 

This  intestine  being  in  contact  with  the  posterior  sur- 
face of  the  pelvis,  is  covered,  on  its  anterior  surface  only, 
by  the  peritoneum  which  lines  the  posterior  surface  of  the 
pelvis;  and  it  is  fixed  in  this  situation  by  the  peritoneum, 
as  the  colon  is  on  the  right  and  left  sides  of  the  abdomen, 
but  more  loosely;  and  therefore  the  term  Mesorectum  has 

* Morgagni  and  Haller  supposed  it  to  be  commonly  on  the  lelt  of 
the  middle  line;  Sabatier  on  the  right. 


121 


Structure  of  the  Rectum. 

sometimes  been  applied  to  that  portion  of  the  peritoneum 
which  is  analogous  to  the  mesentery  and  mesocolon.  The 
peritoneum  does  not  extend  to  the  end  of  the  rectum;  for 
it  is  reflected  at  the  lower  part  of  the  pelvis  from  the  rec- 
tum to  the  bladder,  or  uterus,  and  does  not  line  the  bot- 
tom of  the  pelvis;  so  that  the  lower  part  of  this  intestine, 
as  well  as  of  the  other  viscera  of  the  pelvis,  is  below  the 
peritoneum,  and  not  connected  with  it. 

The  muscular  coat  of  the  rectum  is  much  thicker  and 
stronger  than  that  of  any  other  intestine.  The  strata  of 
longitudinal  and  circular  fibres  which  compose  it  are  very 
distinct  from  each  other.  The  longitudinal  fibres  are  most 
numerous,  and  terminate  at  the  insertion  of  the  fibres  of 
the  levator  ani  muscle.  The  lower  circular  fibres  are  in- 
timately connected  with  the  sphincter  ani. 

The  internal  coal  is  very  vascular,  but  the  villous  struc- 
ture is  not  apparent.  Mucous  follicles  are  also  very  nu- 
merous; and  there  are  likewise  some  distinct  glandular 
bodies  exterior  to  this  coat,  which  vary  in  size  in  dif- 
ferent subjects. 

The  quantity  of  mucus  discharged  from  the  rectum  in 
certain  cases  of  disease,  is  sometimes  very  great.  The  in- 
ternal coat,  in  consequence  of  the  contraction  of  the  cir- 
cular fibres  exterior  to  it,  sometimes  forms  longitudinal 
folds,  which  have  been  called  its  columns;  these  often 
disappear  when  the  intestine  is  opened  lengthways  and 
spread  out.  By  the  contraction  of  the  longitudinal  fibres, 
the  internal  coat  is  often  thrown  into  folds  or  doublings, 
that  must  assume  a transverse  or  circular  direction:  they 
occasionally  pass  down  through  the  sphincter,  and  form 
the  prolapsus  ani.  The  rectum  is  most  plentifully  suppli- 
ed with  bloodvessels,  to  be  described  hereafter;  and  it 
may  be  observed,  that,  on  the  lower  part  of  the  internal 
coat,  the  veins  arc  particularly  numerous. 

The  internal  coat  of  the  rectum  terminates  abruptly 
just  within  the  anus,  and  is  united  to  a production  of  the 
Vol.  II.  Q 


122  Absorbents  and  Nerves  of  the  Intestines. 

skin,  which,  like  the  covering  of  the  lips,  is  very  delicate 
and  vascular,  and  has  an  epithelium,  or  very  thin  cuticle, 
spread  over  it.  The  levator  and  sphincter  ani  muscles, 
with  which  the  termination  of  the  rectum  is  invested, 
are  described  in  the  first  volume. 

The  Absorbents  of  the  Intestines  are  commonly  deno- 
minated Lacteals.  They  originate  on  the  internal  surfaces 
of  these  viscera,  as  has  been  already  described.  After 
passing  through  the  lymphatic  glands,  which  are  so  nu- 
merous on  the  mesentery,  they  generally  unite  and  form 
one  of  the  great  trunks  which  compose  the  thoracic  duct. 
It  is  asserted,  that  some  of  the  absorbent  vessels  of  the 
lower  intestines  unite  to  the  lymphatics  of  the  loins. 

The  Nerves  of  the  Intestines  are  principally  derived 
from  the  intercostals,  or  great  sympathetics.  From  each 
of  these  nerves,  while  they  are  in  the  thorax,  an  impor- 
tant branch,  called  the  ramus  splanchnicus,  arises.  These 
splanchnic  branches  pass  through  the  diaphragm,  and  are 
the  chief  contributors  to  the  ganglions  and  plexuses 
formed  in  the  abdomen.  A plexus  derived  from  this 
source  surrounds  the  superior  mesenteric  artery,  and 
another  the  inferior  mesenteric;  and  from  these  proceed 
the  nerves  of  the  intestines. 


The  Omentum 

Requires  a separate  description,  although  several  cir- 
cumstances connected  with  its  structure  have  been  al- 
ready noticed.  It  often  varies  in  its  position;  but  when  it 
is  rendered  firm  by  a quantity  of  adipose  matter,  it  is 
spread  over  the  intestines  like  an  apron,  extending  from 
the  lower  edge,  or  great  curvature  of  the  stomach,  towards 
the  bottom  of  the  abdomen. 

As  has  been  already  said,  it  is  an  extension  of  the  pe- 
ritoneum, in  two  laminae,  from  the  concave  surface  of  the 
liver  to  the  lesser  curvature  of  the  stomach;  and  these 


123 


Origin  and  Arrangement  of  the  Omentum. 

laminae,  after  surrounding  the  stomach,  come  in  contact 
with  each  other  near  its  great  curvature.  From  this  por- 
tion of  the  stomach,  from  the  commencement  of  the  duo- 
denum, and  also  from  the  spleen,  the  Omentum , composed 
of  two  laminae,  descends  over  the  colon  and  the  small  in- 
testines more  or  less  low  into  the  abdomen;  it  is  then 
folded  backwards  and  upwards,  and  is  continued  until  it 
meets  the  great  arch  of  the  colon:  here  the  laminae  again 
separate  and  inclose  that  portion  of  the  intestine,  on  the 
posterior  side  of  which  they  again  approach  each  other, 
and  form  a membrane  like  the  mesentery,  of  two  laminae, 
which  passes  from  the  concave  or  posterior  surface  of  the 
colon  to  the  back  of  the  abdomen,  where  it  is  continued 
into  the  membrane  which  lines  that  surface.  This  last 
portion  is  the  Mesocolon:  the  portion  between  the  liver 
and  stomach  is  called  the  Omentum  of  Winslow , or  the 
lesser  omentum;  and  the  great  portion  between  the  sto- 
mach and  colon  is  called  the  Great  Omentum , or  the 
omentum  gastro  colicum.  There  is  also  a process  of  pe- 
ritoneum continued  from  that  portion  of  the  colon  which 
is  on  the  right  side  of  the  abdomen,  and  from  the  caecum, 
which  extends  to  some  distance;  it  is  formed  of  two  la- 
minae, that  compose  a cavity  of  an  angular  form.  This 
has  been  called  the  Omentum  Colicum. 

The  great  and  small  omentum,  with  a portion  of  the 
peritoneum  on  the  back  of  the  abdomen,  form  a sac, 
which  incloses  a distinct  cavity  in  the  abdomen.  The  an- 
terior part  of  this  sac  is  composed  of  two  laminae,  and 
between  these  laminae  are  the  stomach  and  the  great  arch 
of  the  colon.  This  cavity,  formed  by  the  two  omenta, 
communicates  with  the  general  cavity  of  the  abdomen  by 
a foramen  of  a semicircular  form,  which  is  behind  the 
great  cord  of  the  vessels  that  go  to  the  liver. 

The  omentum  is  so  delicate  in  structure,  that,  when 
free  from  fat,  it  is  very  liable  to  laceration  merely  by  ad- 
hering to  the  fingers,  if  they  are  dry.  Winslow  therefore 


124  Varieties  in  the  Appearance  of  the  Omentum. 

advised  that  some  unctuous  substance  should  be  rubbed 
on  the  hands,  before  they  were  applied  to  it. 

The  appearance  of  the  great  omentum  is  very  different 
in  different  persons.  In  the  emaciated,  it  appears  like  a 
delicate  transparent  membrane;  in  the  corpulent,  it  is  like 
a broad  mass  of  adeps,  which  sometimes  is  very  thick. 
When  it  is  thus  loaded  with  adeps,  it  is  most  commonly 
spread  over  the  small  intestines:  when  it  is  free  from  fat, 
it  is  often  compressed  together,  so  as  to  form  a small 
mass  near  the  arch  of  the  colon,  on  the  left  side. 

The  principal  bloodvessels  of  the  omentum  are  derived 
from  those  of  the  stomach,  and  are  called  gastro  epiploic 
arteries  and  veins. 

The  use  of  this  membrane  in  the  animal  economy  has 
not  been  ascertained  with  certainty.  It  seems  probable 
that  one  of  its  principal  objects  is  to  protect  the  small 
intestines,  and  lessen  the  friction  consequent  upon  their 
motion;  but  it  has  been  supposed  to  answer  several  other 
important  purposes.* 

* See  Halleri  Elements  Physiologise,  vol.  VI.  pag:  381. 

Gavard.  Traite  de  Splanchnologie,  page  350. 

Dr.  James  Rush’s  Inquiry  into  the  use  of  the  Omentum. 


125 


CHAPTER  III. 

OF  THE  LIVER,  THE  PANCREAS,  AND  THE  SPLEEN. 

SECTION  I. 

Of  the  Liver. 

THIS  largest  viscus  of  the  abdomen,  when  in  a healthy 
condition,  is  of  a reddish  brown  colour.  If  it  is  taken  out  of 
the  subject,  and  laid  on  a flat  surface,  it  is  flat,  but  in  the 
abdomen  it  is  convex  and  concave. 

It  is  situated  in  the  right  hypochondriac  region,  which  it 
occupies  entirely;  and  extends  through  the  upper  portion 
of  the  epigastric  into  the  left  hypochondi  iac  region.  Being 
placed  immediately  under  the  diaphragm,  and  in  close 
contact  with  it,  as  well  as  with  the  inner  surface  of  the 
right  hypochondriac  region,  it  partakes  of  their  form,  and 
is  convex  above  and  concave  below.  When  thus  situated, 
it  is  of  an  irregular  figure,  between  the  circle  and  the  oval, 
but  it  is  broader  at  the  right  extremity  than  at  the  left,  and 
very  irregular  in  thickness.  The  edge  or  margin  which 
is  in  contact  with  the  posterior  part  of  the  right  hypochon- 
driac region,  is  very  thick.  It  gradually  becomes  thinner 
towards  the  left,  and  also  towards  the  front;  so  that  the 
right  margin,  and  a large  portion  of  the  posterior  margin, 
is  very  thick,  while  the  left  and  the  anterior  margin  is 
thin. 

The  upper  convex  surface  of  the  liver,  when  in  its  na- 
tural situation,  is  smooth:  the  lower  concave  surface  is 
marked  by  several  grooves  or  fissures  and  eminences. 
One  of  these,  called  the  Umbilical  or  the  great  fissure, 


126  Lobes  and  Fissures  of  the  Liver. 

commences  at  a notch  in  the  anterior  edge  of  the  liver,  to 
the  left  of  the  middle,  and  continues  to  the  posterior  edge. 
At  the  commencement  of  this  fissure  the  umbilical  liga- 
ment enters;  and  at  the  termination,  or  near  it,  the  vena 
cava  is  situated.  Opposite  to  this  fissure,  on  the  upper  or 
convex  surface,  is  a ligament  passing  from  the  diaphragm 
to  the  liver,  which  is  called  the  falciform.  The  fissure  and 
the  ligament  divide  the  liver  into  its  two  great  lobes,  the 
Right  and  Left . 

Another  great  fssure,  called  the  transverse  or  principal , 
commences  in  the  right  lobe  and  extends  to  the  left,  cross- 
ing the  first  mentioned  fissure  at  right  angles,  and  extend- 
ing a very  short  distance  beyond  it.  It  is  very  deep,  and 
rather  nearer  to  the  posterior  than  the  anterior  edge  of  the 
liver.  In  this  fissure,  near  to  its  right  extremity,  the  great 
vein,  called  vena  portarum,  and  the  hepatic  artery  enter, 
and  the  excretory  duct  of  the  liver,  commonly  called  the 
hepatic  duct,  comes  out.  About  the  middle  of  the  fissure 
are  two  prominences,  one  on  each  side;  these  were  called 
the  portas,  or  gates  of  the  liver,  and  hence  the  great  vein 
was  called  vena  portarum.  This  vein  has  two  very  large 
rectangular  branches,  which  constitute  what  is  called  the 
sinus  of  the  vena  portarum,  and  they  occupy  the  principal 
extent  of  the  fissure. 

The  liver  is  in  close  contact  with  the  vena  cava  behind; 
and  there  is  either  a groove  in  it  for  the  passage  of  the 
vein,  or  this  great  vessel  is  completely  inclosed  by  it. 
There  is  also  an  excavation  on  the  lower  surface  of  the 
liver,  which  is  occupied  by  a portion  of  the  gall  bladder. 

Besides  the  great  lobes  above  mentioned,  there  are 
also  two  or  three  prominent  parts  on  the  concave  surface, 
which  are  denominated  lobes.  One  of  these,  called  Lobulus 
Spigelii , is  oblong,  with  two  sides,  and  an  angle  continued 
along  its  whole  length,  which  extends  from  the  transverse 
fissure  to  the  posterior  margin  of  the  liver.  It  is  situated 


127 


Ligaments  of  the  Liver. 

between  the  posterior  part  of  the  transverse  fissure,  or 
ductus  venosus,  and  the  vena  cava. 

The  anterior  extremity  of  this  lobe,  which  forms  one 
of  the  margins  of  the  transverse  fissure,  is  somewhat  bi- 
furcated, and  has  been  called  lobulus  caudatus.  The 
largest  portion  of  the  bifurcated  end  forms  a process 
like  a papilla. 

Between  the  umbilical  fissure  and  the  depression  for 
the  gall  bladder  is  a protuberant  space,  which  varies  from 
an  inch  and  a quarter  to  two  inches  in  breadth.  This  has 
also  been  called  a lobe,  Lobulus  Quartus  or  Anonymus. 

The  peritoneum  is  extended  from  the  surface  of  the 
abdomen  to  the  surface  of  the  liver,  in  such  manner  as 
to  cover  it,  and  to  form  ligaments,  which  have  a great 
effect  in  retaining  it  in  its  proper  situation.  The  whole 
posterior  edge  of  the  liver  is  in  contact  with  the  back  of 
the  abdomen.  The  peritoneum  above  the  liver  is  reflect- 
ed to  the  upper  surface  of  it,  and  the  peritoneum  below 
it  to  the  lower  surface;  so  that  two  laminae  of  the  perito- 
neum pass  from  the  lower  part  of  the  diaphragm  at  the 
back  of  the  abdomen  to  the  posterior  edge  of  the  liver. 
These  processes  of  the  peritoneum  are  considered  as 
forming  two  ligaments,  which  are  called  the  right  and  left 
lateral  ligaments.  A portion  of  the  posterior  surface  of 
the  liver,  uncovered  by  the  peritoneum,  is  often  in  con- 
tact with  a portion  of  the  tendon  of  the  diaphragm,  also 
uncovered  by  peritoneum:  around  this  place  of  contact, 
the  peritoneum  is  extended  from  the  diaphragm  to  the 
liver,  and  thus  forms  what  has  been  called  the  coronary 
ligament  of  the  liver. 

The  peritoneum  of  the  right  side  of  the  diaphragm, 
and  of  the  abdominal  muscles,  as  far  down  as  the  umbi- 
licus, is  extended  to  the  liver,  and  joins  it  on  the  con- 
vex surface  immediately  opposite  to  the  umbilical  fis- 
sure. The  peritoneum  from  the  left  side  of  these  parts 
does  the  same;  and  as  these  reflections  of  the  peritoneum 


12S 


Mode  of  supporting  the  Liver. 

are  continued  from  so  low  a part  as  the  umbilicus,  they 
are  extended  not  only  to  the  convex  surface  of  the  liver, 
but  also  to  the  great  notch,  and  along  the  umbilical 
fissure. 

From  the  umbilicus  proceeds  a round  cord-like  liga- 
ment, which  in  the  foetal  state  was  a vein,  that  passes  to 
the  great  fissure  of  the  liver,  and  along  it.  The  process 
of  the  peritoneum  abov  e mentioned  is  so  connected  with 
this  cord,  that  it  incloses  it  in  its  lower  edge,  and  the 
whole  is  called  the  falciform  ligament  of  the  liver.  The 
cord,  when  named  separately,  is  the  umbilical  or  the 
round  ligament;  and  the  membrane  or  lamina  of  the  pe- 
ritoneum forms  the  suspensory  ligament.  Besides  these, 
the  peritoneum  on  the  lower  side  of  the  liver  is  so  ar- 
ranged, that  it  not  only  extends  to  the  stomach,  but  to 
the  duodenum  and  the  colon. 

By  these  ligaments  the  position  of  the  liver  must  be 
fixed  to  a great  degree;  and  there  is  one  additional  con- 
nection, which  must  have  a great  effect  in  retaining  it  in 
its  proper  situation.  The  vena  cava  receives  two  or  three 
great  veins  from  the  liver,  at  the  place  where  it  is  in  con- 
tact with  the  posterior  edge  of  that  viscus;  these  veins  of 
course  pass  directly  from  the  substance  of  the  liver  into 
the  cava,  and  connect  it  to  that  vessel.  As  the  cava  is 
supported  by  the  heart,  and  also  by  the  diaphragm,  it 
must  afford  a considerable  support  to  the  liver. 

When  the  stomach  and  intestines  are  distended,  they 
must  also  contribute  in  a considerable  degree  to  the  sup- 
port of  the  liver. 

The  liver  has  a strong  tendency,  when  we  are  erect, 
to  change  its  situation;  and  some  considerable  support  is 
necessary  to  counteract  this  tendency.  It  would  move  to 
the  right,  when  we  lie  on  the  right  side,  if  it  were  not  in 
contact  with  the  ribs;  and  it  inclines  to  the  left,  for  want 
of  such  support,  when  we  lie  on  the  left  side. 

It  has  been  computed,  that  the  liver  descends  about  two 


Acini  of  the  Liver.  Proper  Coat  of  the  Liver.  129 

inches,  when  the  position  of  the  subject  is  changed  from 
the  horizontal  to  the  erect.  As  it  is  in  contact  with  the 
diaphragm,  it  is  obvious  that  it  must  be  influenced  by  the 
motions  of  that  muscle,  and  that  it  must  descend  when 
the  diaphragm  contracts. 

The  liver  is  composed  of  a substance  which  has  some 
firmness  of  consistence,  although  it  is  yielding;  and  is  also 
somewhat  brittle  or  friable.*  When  cut  into,  the  sections 
of  many  tubes,  or  vessels  of  different  diameters,  appear  on 
the  cut  surface.  When  the  texture  of  this  substance  is 
more  closely  examined,  it  appears  somewhat  granulated, 
or  composed  of  very  small  bodies,  which  were  called  acini 
by  the  anatomists  who  first  described  them.  The  whole 
substance  is  inclosed  by  the  peritoneum,  which  is  ex- 
tended to  it  from  the  surface  of  the  abdomen  in  the 
manner  that  has  been  already  described.  It  has  also  a' 
proper  coat  or  capsule;  and  on  the  posterior  edge,  where 
the  laminae  of  the  lateral  ligaments  pass  from  the  dia- 
phragm to  the  liver,  at  some  distance  from  each  other, 
a portion  of  the  liver,  covered  by  this  coat  and  by  cellular 
substance,  is  in  contact  with  the  diaphragm.  The  same 
thing  occurs  likewise  at  the  coronary  ligament. f 

The  liver  holds  the  first  place  among  the  glands  of  the 
body  for  size,  but  it  is  still  more  remarkable  for  some 
other  circumstances  in  its  economy.  In  addition  to  an  ar- 
tery, which  passes  to  it  as  arteries  do  to  other  glands, 
there  is  a large  vein  which  also  enters  it  as  an  artery;  and 
after  ramifying  throughout  the  liver,  communicates,  as 
does  the  artery,  with  other  veins,  which  carry  the  blood 
from  this  gland  into  the  vena  cava  and  the  general  circu- 

* It  has  been  fractured  in  the  living  body  by  external  violence. 

t Many  anatomists  deny  the  existence  of  this  coat;  but  if  one  of  the 
laminae  of  the  ligaments  be  carefully  peeled  off  from  the  surface  of  a 
liver  which  is  slightly  affected  by  putrefaction,  it'  will  be  apparent, 
although  very  thin.  It  was  described  by  M.  Laennec,  in  Le  Journal 
de  Medecine  for  1803. 

Yol.  II. 


R 


130  Vessels  of  the  Liver.  Hepatic  Artery. 

lafion.  There  are  therefore  three  species  of  bloodvessels 
in  the  liver;  and  with  these  are  found  the  vessels  which 
carry  out  of  the  gland  the  fluid  secreted  by  it,  or  the  bile. 

The  artery  of  the  liver  is  denominated  the  Hepatic  Ar- 
tery 'Flie  vein  which  goes  to  the  liver  is  called  the  Vena 
Portarum,  from  the  place  at  which  it  enters.  The  veins 
which  carry  to  the  vena  cava  the  blood  brought  to  the  li- 
ver by  the  hepatic  artery  and  the  vena  portarum,  are  called 
the  Hepatic  Veins;  and  the  duct  through  which  the  bile 
flows  out  of  the  liver,  is  called  the  Hepatic  Duct.  Three 
of  these  vessels,  the  Hepatic  Artery , the  Vena  Portarum , 
and  the  Hepatic  Duct , enter  the  liver  at  the  great  fissure, 
at  the  spot  where  the  prominences  exist  called  the  poi  ae; 
hence  the  name  vena  portarum  was  applied  to  the  vein. 

These  vessels  ramify  in  the  manner  presently  to  be 
described;  and  it  is  ascertained  by  minute  anatomical  in- 
vestigation, that  the  liver  is  entirely  composed  of  the  ra- 
mifications of  these  vessels  and  of  the  hepatic  veins,  with 
absorbent  vesselsand  nerves,  which  are  connected  together 
by  cellular  membrane. 

It  has  been  already  observed,  that  the  first  great  branch 
sent  off  by  the  aorta  in  the  abdomen,  the  Cceliac,  divides 
into  three  branches,  which  go  respectively  to  the  stomach, 
the  liver,  and  the  spleen. 

The  Hepatic  is  generally  the  largest  of  these  branches. 
In  its  progress  towards  the  liver  it  sends  off  an  artery  to 
the  stomach,  called  the  gastrica  dextra.  At  the  great  fis- 
sure it  divides  into  two  branches:  the  right  branch,  w’hich 
supplies  the  right  lobe  of  the  liver,  is  of  course  the  largest. 
This  branch  sends  off  one  to  the  gall  bladder,  which  is  call- 
ed the  cystic  artery;  and  also  some  smaller  branches:  it 
passes  under  the  hepatic  duct,  and  ramifies  through  the 
great  lobe  of  the  liver.  The  left  branch  is  distributed 
through  the  left  lobe  of  the  viscus.  It  can  be  proved  by 
injection,  that  the  hepatic  artery  communicates  not  only 
with  the  hepatic  veins,  but  with  the  biliary  duct,  and  the 


Vena  Portarum. 


131 


vena  portarum  also.  It  has  been  disputed  whether  the  size 
of  this  arterv  is  greater  than  would  be  requisite  for  the 
nourishment  and  animation  of  the  liver. 

The  Vena  Portarum , the  great  peculiarity  of  the  liver, 
originates  from  all  the  chylopoietic  viscera  except  the  li- 
ver, and  is  of  course  formed  by  the  union  of  the  veins 
which  correspond  to  all  the  branches  of  the  coeliac  and 
mesenteric  arteries,  as  they  are  distributed  to  the  stomach 
and  intestines,  the  spleen,  the  pancreas,  and  the  omentum. 
The  veins  from  the  intestines  generally  form  two  great 
trunks,  w ich  are  denominated  the  greater  and  lesser  ine- 
sentric  veins.  The  great  mesentric  vein  is  situated  to 
the  right,  and  rather  before  the  mesenteric  artery.  After 
it  has  approached  the  origin  of  the  artery  it  separates 
from  it,  and  passes  behind  the  pancreas:  at  this  place, 
nearly  in  front  of  the  spine,  it  is  joined  by  the  great  vein 
of  the  spleen,  which  forms  almost  a right  angle  with  it, 
and  these  constitute  the  great  trunk  of  the  vena  portarum. 
The  lesser  mesenteric  vein,  which  corresponds  to  the  in- 
ferior mesenteric  artery,  and  brings  blood  from  the  pelvis 
and  from  the  left  part  of  the  colon,  becomes  finally  a large 
vessel,  and  commonly  unites  with  the  splenic  about  an  inch 
and  a half  before  its  junction  with  the  superior  mesenteric 
vein.  The  vena  portarum,  thus  formed,  proceeds  towards 
the  liver,  inclining  to  the  right,  and  is  generally  about 
three  inches  in  length:  in  its  course  it  sometimes  receives 
small  veins,  which  in  other  cases  pass  to  its  splenic  and 
mesenteric  branches.  When  it  has  arrived  at  the  great 
transverse  sinus  of  the  liver,  it  divides  into  two  large 
branches,  each  of  which  forms  nearly  a right  angle  with 
it.  Their  size  is  so  great,  that,  when  distended  with  in- 
jection, they  appear  like  an  independent  vessel,  into  which 
the  vena  portarum  enters;  and  on  this  account  they  are 
called  the  great  Sinus  of  the  vena  portarum.  They  do  not 
adhere  firmly  to  the  glandular  substance  of  the  liver,  but 
are  united  to  it  by  cellular  membrane.  The  right  branch 


132 


Hepatic  Duct.  Hepatic  Veins. 

is  the  widest  and  shortest.  It  generally  divides  into  three 
branches;  an  anterior,  a posterior,  and  a lateral  branch; 
which  ramify  minutely,  and  extend  themselves  in  the  right 
lobe.  The  left  branch  is  much  longer,  and  continues  to  the 
extent  of  the  great  fissure.  Near  its  termination  it  is  join- 
ed by  the  umbilical  ligament,  which  has  been  already 
mentioned.  This  branch  is  generally  in  contact  with  a 
branch  of  the  hepatic  artery  and  of  the  hepatic  duct;  and 
ramifies,  like  the  right  branch,  into  the  contiguous  parts 
of  the  liver. 

The  Hepatic  or  excretory  duct  originates,  by  very  small 
vessels,  from  the  acini  or  corpuscles  of  which  the  liver  is 
composed,  and  into  which  the  minute  ramifications  of 
the  vena  portarum  and  hepatic  artery  extend.  They  ac- 
company these  vessels,  increasing  as  they  increase,  al- 
though the  fluid  they  contain  moves  in  an  opposite  direc- 
tion; and  two  large  branches  which  they  ultimately  form 
are  situated  at  the  portae  of  the  liver,  in  contact  with 
the  great  branches  of  the  vena  portarum  and  the  hepatic 
artery. 

These  three  vessels  are  in  contact  with  each  other  be- 
fore they  enter  the  liver.  The  biliary  duct  is  anterior,  the 
vena  portarum  posterior,  and  the  artery  to  the  left  of 
them.  They  are  accompanied  by  nerves  and  lymphatic 
vessels,  and  are  surrounded  by  a considerable  quantity 
of  cellular  substance,  and  thus  arranged  are  partially  co- 
vered with  peritoneum.  The  cellular  substance  which 
invests  them  continues  with  them  into  the  liver,  and  is 
more  particularly  connected  with  the  vena  portarum,  It 
is  called  Glisson’s  Capsule , and  was  supposed  to  have 
some  contractile  power,  which  assisted  the  circulation  of 
the  vena  portarum;  but  that  idea  is  now  altogether  aban- 
doned. The  hepatic  veins,  which  receive  the  blood  of 
the  hepatic  artery  and  the  vena  portarum,  open  into  the 
anterior  part  of  the  vena  cava,  where  it  is  in  contact  with 
the  liver.  Generally  there  are  three  of  these  veins,  but 


Nerves  of  the  Liver.  Lymphatics.  13S 

sometimes  there  are  only  two;  in  which  case  one  of  them 
is  formed  by  two  others,  which  unite  immediately  before 
they  open  into  the  vena  cava.  It  is  to  be  observed,  that 
the  various  branches  of  these  veins  do  not  accompany 
those  branches  of  the  vena  portarum  or  hepatic  artery  to 
which  they  correspond,  but  form  very  large  angles  with 
them.  This  is  probably  owing  merely  to  their  termina- 
tion in  a part  so  distant  from  that  in  which  the  artery 
and  the  vena  portarum  originate;  but  it  is  very  different 
from  what  occurs  in  other  glands. 

The  Nerves  of  the  Liver  are  derived  from  the  semilu- 
nar ganglions  of  the  splanchnic  nerves.  From  these  many 
nerves  proceed,  which  form  a network  denominated  the 
solar  plexus.  From  this  plexus  many  threads  are  sent  off, 
which  form  a network  that  is  divided  into  the  right  and 
left  1 icpatic  plexus.  These  plexuses  surround  the  hepatic 
artery  and  the  vena  portarum,  and  accompany  them  in 
their  ramifications  throughout  the  liver,  being  inclosed  by 
Glisson’s  capsule.  They  receive  some  threads  from  the 
stomachic  plexus,  formed  by  the  par  vagum.  Although 
the  number  of  nervous  fibres  is  ver)^  considerable,  their 
bulk,  compared  with  that  of  the  liver,  is  very  small. 

The  Lymphatics  of  the  Liver  are.  extremely  numerous; 
and  those  in  that  portion  of  the  peritoneum  which  invests 
the  liver  may  easily  be  rendered  conspicuous:  for  by 
pressure  the  injected  fluid  can  be  forced  from  the  trunks 
and  large  branches  into  the  small  ramifications,  in  oppo- 
sition to  the  valves.  When  all  the  surface  is  injected  in 
this  manner,  it  has  the  colour  of  the  substance  injected; 
as  is  the  case  with  parts  which  are  very  vascular,  when 
when  the  bloodvessels  are  injected. 

The  deep-seated  lymphatics  are  also  very  numerous 
in  the  liver,  and  communicate  freely  with  the  superficial. 

The  superficial  lymphatics  which  are  on  the  upper 
surface,  proceed  through  the  diaphragm  into  the  thorax 
in  their  course  to  the  thoracic  duct.  Those  which  are 


134 


Glandular  Substance  of  the  Liver. 

deep  seated  emerge  from  the  liver  at  the  portte,  where 
the  great  vessels  enter,  and  unite  with  the  thoracic  duct  in 
the  abdomen,  after  passing  through  several  glands.  The 
lymphatics  of  the  lower  surface  unite  with  the  deep- 
seated. 

The  glandular  or  parenchymatous  substance  of  the 
liver  is  of  a reddish  brown  colour,  and  moderately  firm 
consistence.  When  it  is  cut  into,  the  cut  surface  exhibits 
the  sections  of  the  branches  of  the  different  bloodvessels 
above-mentioned,  and  of  the  excretory  ducts.  These  ves- 
sels are  often  distinguishable  from  each  other.  The  sec- 
tion of  the  biliary  duct  appears  the  thickest;  that  of  the 
artery  next;  the  vena  portarum  is  next  in  order;  and,  last 
of  all,  the  venae  hepaticae. 

The  branches  of  the  vena  portarum  are  surrounded  by 
cellular  substance,  or  Glisson’s  capsule;  and  therefore 
adhere  less  to  the  substance  of  the  liver  than  the  branches 
of  the  hepatic  veins.  The  sections  of  the  hepatic  ducts 
have  often  bile  in  them,  and  are  therefore  termed  pori 
biliarii.  The  branches  of  the  artery  are  also  very  distin- 
guishable. 

When  the  internal  substance  of  the  liver  is  brought  into 
view,  and  examined  accurately,  it  appears  to  be  formed 
of  small  bodies,  or  acini,  which  are  distinguishable  from, 
each  other.  If  the  liver  happens  to  be  torn  or  lacerated, 
the  lacerated  surfaces  are  rough  and  irregular,  owing  to 
the  separation  of  these  acini  from  each  other. 

It  is  asserted  by  several  microscopical  observers,  that  a 
minute  branch  of  each  of  the  aforesaid  vessels  can  be 
traced  into  each  of  the  acini.  It  is  also  declared,  that  if 
each  of  these  vessels  be  injected  separately  with  mercury, 
oil  of  turpentine  coloured,  or  a saturated  aqueous  solution 
of  gutta  gamba,  there  is  no  part  of  the  glandular  mass  as 
large  as  a grain  of  mustard  seed  in  which  these  vessels 
will  not  be  found. 

Several  anatomists  of  the  first  character  have  likewise 


135 


Peculiarity  of  the  Liver. 

declared,  that  a fluid  properly  injected  into  one  of  these 
vessels,  will  occasionally  pass  into  all  of  them.  Thus  an 
injection  will  not  only  pass  from  the  vena  portarum  to  the 
biliary  duct,  but  to  the  hepatic  artery  and  veins  also.  It 
will  likewise  pass,  in  a retrograde  course,  from  the  biliary 
ducts  to  the  vena  portarum,  and  to  the  hepatic  artery  and 
the  hepatic  veins;  or  from  any  one  of  the  four  orders  of 
vessels  into  the  three  others. 

The  great  peculiarity  of  the  liver  is,  that  venous  blood, 
instead  of  arterial,  is  brought  .to  it  for  the  purpose  of  se- 
cretion. Thus,  the  great  vein  of  the  chylopoietic  viscera, 
instead  of  passing  to  the  cava,  enters  the  liver  by  the 
transverse  fissure,  and  takes  on  the  office  of  an  artery;  its 
coats,  on  this  account,  being  much  thicker  and  stronger 
than  those  of  the  hepatic  veins.* 

The  Biliary  or  Hepatic  Duct  is  formed  of  very  mi- 
nute vessels,  which  originate  in  the  acini  above  described; 
these  unite  together  like  veins  until  they  form  considera- 
ble branches,  which  finally  compose  the  great  ramifications 
of  the  biliary  duct.  This  duct  is  very  strong  and  firm,  and 
on  its  internal  surface  are  the  orifices  of  many  mucous 
follicles  or  ducts.  It  passes  from  the  transverse  fissure 
of  the  liver,  with  the  hepatic  artery,  as  before  described, 
and,  at  the  distance  of  an  inch  and  a half  or  two  inches 
from  the  fissure,  it  unites  with  a duct  from  the  gall  blad- 
der, which  is  called  the  Cystic  Duct.  This  duct  is  nearly 
equal  in  length  to  the  hepatic,  and  after  running  almost 
parallel  to  it,  at  length  unites  so  as  to  form  an  acute  angle 
with  it.  The  cystic  duct  is  smaller  than  the  hepatic,  and 
they  unite  much  like  two  branches  of  an  artery. 

* A case  is  related  by  Mr.  Abernethy,  in  the  London  Philosophical 
Transactions,  in  vvhichthe  vena  portarum  terminated  in  the  vena  cava 
below  the  liver,  without  communicating  with  it.  The  hepatic  artery 
was  the  only  vessel  which  carried  blood  to  the  organ,  and  was  un- 
usually large;  the  liver  being  nearly  of  the  natural  size.  Some  bile 
was  in  the  gall  bladder)  but  it  was  less  acrid  than  usual. 


136 


Gall  Bladder. 


The  Gall  Bladder , from  which  the  cystic  duct  arises,  has 
the  shape  of  a pear,  with  a very  long  neck,  curved  in  a 
way  to  be  hereafter  described.  It  is  situated  in  a superficial 
pit  or  cavity  in  the  concave  surface  of  the  right  lobe  of  the 
liver;  and  its  fundus,  or  basis,  often  projects  a small  dis- 
tance beyond  the  anterior  edge  of  the  viscus.  Its  position 
is  such,  that  it  extends  from  before  backwards,  and  in- 
clines rather  to  the  left;  of  course,  therefore,  when  the 
subject  lies  on  his  back,  the  bottom  of  the  bladder  is  the 
uppermost  part  of  it;  when'  he  lies  on  the  left  side,  it  is 
also  higher  than  the  neck;  and  when  he  lies  on  the  right 
side,  it  is  the  lowermost. 

The  gall  bladder  consists  of  an  internal  coat,  and  one 
that  is  cellular  or  nervous,  and  has  somewhat  of  a fibrous 
appearance.  This  coat  connects  the  gall  bladder  to  the 
surface  of  the  pit  or  cavity  in  which  it  lies.  The  perito- 
neal coat  of  the  liver  is  extended  from  the  surface  of  the 
viscus  over  that  part  of  the  surface  of  the  gall  bladder 
which  is  not  in  contact  with  it. 

The  internal  coat  has  a peculiar  structure,  with  a faint 
resemblance  to  that  of  the  villous  membrane.  It  is  so  ar- 
ranged as  to.  form  very  fine  folds,  which  have  various 
directions:  in  some  places  they  make  a network;  in  others, 
as  the  neck  of  the  bladder,  they  are  longitudinal.  Many 
mucous  follicles  exist  on  its  internal  surface. 

The  neck  of  the  gall  bladder  is  suddenly  bent  down  or 
curved  upon  itself,  and  twisted,  so  that  it  resembles  the 
neck  of  the  swan,  when  the  head  of  that  bird  is  applied  to 
one  side  of  its  breast. 

A branch  of  the  hepatic  artery,  which  leaves  it  before 
it  enters  the  liver,  is  appropriated  to  the  gall  bladder,  and 
is  therefore  denominated  the  cystic  artery.  The  veins 
corresponding  to  this  artery  empty  themselves  into  the  vena 
portarum .*  The  lymphatic  vessels  are  united  to  those 

* It  has  been  justly  observed  by  John  Bell,  that  the  veins  would 
not  terminate  thus,  if  bile  were  secreted  by  the  gall  bladder. 


Ductus  Communis  Choledochus.  The  Bile.  137 


which  are  found  on  the  lower  surface  of  the  liver,  and 
the  nerves  are  derived  from  the  hepatic  plexus. 

The  gall  bladder  appears  to  be  merely  a reservoir,  into 
which  bile  passes  through  its  duct  in  a retrograde  direc- 
tion. If  air  be  blown  through  the  hepatic  duct  from  the 
liver,  it  will  pass  to  the  gall  bladder  almost  as  freely  as  it 
passes  to  the  duodenum. 

The  biliary  duct  from  the  liver,  after  receiving  the  duct 
from  the  gall  bladder,  takes  the  name  of  Ductus  Com- 
munis Choledochus.  It  is  wider  than  either  of  the  other 
ducts,  and  near  three  inches  in  length.  It  passes  down 
before  the  vena  portarum,  and  on  the  right  of  the  hepatic 
artery,  to  the  posterior  surface  of  the  right  extremity  of 
the  pancreas.  It  passes  through  a small  portion  of  that 
gland,  and  then  perforates  the  muscular  coat  of  the  duo 
denum;  after  which  it  proceeds  from  half  an  inch  to  an 
inch  between  this  coat  and  the  villous,  and  opens  into  the 
cavity  of  the  intestine.  The  orifice  forms  a tubercle  which 
extends  lengthways  of  the  intestine,  and  is  rounded  above 
and  pointed  below,  with  a slit  in  it.  While  this  duct  is 
in  contact  with  the  pancreas,  a duct  from  that  gland 
generally  opens  into  it,  so  that  the  biliary  and  pancreatic 
fluids  enter  the  duodenum  by  the  same  orifice;  but  some- 
times the  pancreatic  duct  opens  into  the  duodenum  by  a 
distinct  orifice,  very  near  to  that  of  the  biliary  duct. 

The  Bile , or  fluid  secreted  by  the  liver,  appears  to  answer 
a two-fold  purpose  in  the  animal  economy.  It  produces 
a chemical  effect  upon  the  alimentary  mixture  which 
passes  from  the  stomach  through  the  intestines;  and  it 
increases  the  peristaltic  motion  of  those  important 
organs. 

By  an  inverted  action  of  the  duodenum,  some  of  this 
fluid  is  frequently  carried  upwards  into  the  stomach:  it 
then  often  produces  only  slight  derangement  of  the 
functions  and  sensations  connected  with  that  viscus;  but 
sometimes  violent  vertigo , and  even  convulsions , seem 

Vol.  II.  S 


138 


The  Bile . 


to  have  arisen  merely  from  the  presence  of  a large  quanti- 
ty of  bile  in  the  stomach;  for  they  have  gone  off  com- 
pletely upon  the  discharge  of  bile  by  vomiting. 

Notwithstanding  these  effects  of  bile  in  certain  cases, 
in  which  a great  deal  of  it  exists  in  the  stomach,  it  is 
often  carried  into  the  mass  of  blood  in  large  quantities, 
and  appears  to  be  mixed  with  the  serum,  and  to  circu- 
late through  the  body,  without  producing  any  very  sen- 
sible effect:  thus  many  persons  who  are  deeply  tinged 
by  bile  in  their  blood,  experience  but  few  effects  that 
can  be  imputed  to  the  mixture  of  it  with  the  circulating 
fluids;  and  neither  the  brain  nor  the  heart  appear  to  be 
much  influenced  by  the  circumstance. 

Bile  is  miscible  with  water  and  with  alcohol,  and  also 
with  oily  substances;  and  it  often  assumes  a green  co- 
lour, when  mixed  with  acids.  The  colour  of  the  alvine 
discharges  is  derived  from  the  bile,  and  they  are  there- 
fore sometimes  very  green,  when  the  acetous  fermen- 
tation takes  place  in  the  contents  of  the  stomach  and 
bowels. 

It  is  asserted  by  some  chemists,  that  ten  parts  in 
eleven  of  the  human  bile  consist  of  water;  that  albu- 
minous matter  composes  about  one  forty-sixth  part  of 
it;  and  that  there  is  nearly  an  equal  quantity  of  resin- 
ous matter  in  it.  There  is  also  a small  quantity  (one 
part  in  244)  of  uncombined  soda  dissolved  in  it,  and  a 
smaller  quantity  of  neutral  salts,  consisting  of  soda 
combined  with  the  phosphoric,  sulphuric  and  muriatic 
acids.  In  addition  to  these  there  is  a very  small  quan- 
tity of  phosphate  of  lime  and  of  oxide  of  iron,  and  some 
yellow  insoluble  matter. 

The  bile  in  the  Gall  Bladder  is  generally  more  vis- 
cid than  that  which  is  found  in  the  Hepatic  Duct. 


The  Pancreas. 


U9 


SECTION  II. 

Of  the  Pancreas. 

THE  pancreas  is  a glandular  body,  which  has  a strong 
resemblance  to  the  salivary  glands  in  several  particulars. 
It  is  nearly  six  inches  in  length,  and  is  irregularly  oblong 
in  its  form,  one  extremity  being  much  larger  than  the 
other.  Its  large  extremity  is  in  contact  with  the  duodenum, 
and  it  extends  from  this  intestine  in  a transverse  direc- 
tion to  the  spleen,  to  which  it  is  connected  by  the  omen- 
tum and  by  bloodvessels.  It  is  not  invested  by  the  peri- 
toneum, but  is  situated  in  the  space  which  exists  between 
the  two  laminae  of  the  mesocolon,  as  they  proceed  from 
the  back  of  the  abdomen,  before  they  come  in  contact 
with  each  other.  It  is  anterior  to  the  aorta  and  vena  cava, 
and  to  the  mesenteric  vein,  or  main  branch  of  the  vena 
portarum;  being  connected  to  these  parts  by  cellular  mem- 
brane. At  the  right  extremity,  which  is  connected  with 
the  duodenum,  is  a process  of  the  gland  that  extends 
downwards  in  close  contact  with  the  intestine.  This  is 
called  the  head  of  the  pancreas,  or  the  lesser  pancreas. 

The  position  of  the  pancreas  is  such,  that  one  of  its  sur- 
faces looks  forwards  and  rather  upwards,  and  the  other 
backwards  and  downwards;  one  edge  is  of  course  poste- 
rior and  superior,  and  the  other  anterior  and  inferior.  The 
posterior  of  these  edges  is  much  thicker  than  the  other, 
and  has  a groove  or  excavation  which  is  occupied  by  the 
splenic  bloodvessels. 

This  gland  differs  from  the  other  large  glands  of  the 
abdomen,  inasmuch  as  it  has  not  a large  artery  particu- 
larly appropriated  to  it;  but  instead  of  this,  it  receives 
branches  from  the  contiguous  arteries. 

The  arterial  blood  of  this  gland  is  partly  supplied  by 
the  splenic  artery,  which,  in  its  course  from  the  main 


140 


Pancreatic  Duct. 


trunk  of  the  cceliac  to  the  spleen,  while  it  is  in  the  groove 
at  the  edge  of  the  pancreas,  sends  off  into  the  gland  one 
considerable  branch  called  the  great  pancreatic,  and  a 
number  of  small  branches,  which  go  off  in  succession. 
In  addition  to  these,  the  pancreas  receives  vessels  from 
one  of  the  branches  of  the  hepatic  artery,  before  it  sends 
off  its  great  ramifications,  as  well  as  small  twigs  from  se- 
veral other  contiguous  arteries.  The  veins  correspond 
with  the  arteries,  but  ultimately  are  discharged  into  the 
vena  portarum. 

The  pancreas  resembles  the  salivary  glands  in  colour, 
and  also  in  texture;  for  it  is  of  a dull  white  colour  with  a 
tinge  of  red,  and  it  appears  to  consist  of  small  bodies  of  a 
granulated  form,  which  are  so  arranged  as  to  compose 
small  masses  or  lobes  that  are  united  to  each  other  by  cel- 
lular membrane.  Each  of  these  granulated  bodies  receives 
one  or  more  small  arterial  twigs,  and  from  it  proceeds  not 
only  a vein  but  a small  excretory  duct,  which  uniting  with 
similar  ducts  from  the  adjoining  granulated  portions  or 
acini,  forms  a larger  duct  in  each  lobe  or  mass;  these  open 
into  the  great  duct  of  the  gland,  which  proceeds  through 
it  lengthwise  from  the  left  extremity,  in  which  it  com- 
mences, to  the  right. 

This  duct  is  situated  in  the  body  of  the  gland,  which 
must  be  dissected  to  bring  it  into  view.  It  is  thin  and 
transparent,  like  the  ducts  of  the  salivary  glands,  and  is 
rather  larger  in  diameter  than  a crow’s  quill.  In  its  pro- 
gress towards  the  right  extremity  of  the  gland  it  gradually 
enlarges,  and  commonly  receives  a branch  from  the  part 
called  the  lesser  pancreas.  It  most  commonly  unites  with 
the  biliary  duct  before  it  opens  into  the  duodenum:  some- 
times these  ducts  open  separately,  but  very  near  to  each 
other.  They  penetrate  the  coats  of  the  intestine  rather 
obliquely,  and  between  four  and  five  inches  from  the  py- 
lorus. This  canal  is  sometimes  called  Ductus  Wirsungi , 
after  an  anatomist  who  published  a plate  of  it. 


141 


Size  of  the  Spleen . 

The  pancreas  has  an  irregular  surface,  and  no  coat 
which  covers  it  uniformly.  It  is  invested  by  cellular  mem- 
brane, which  also  connects  its  different  lobes  to  each 
other.  Absorbent  vessels  and  nerves  are  traced  into  it. 

The  portion  called  the  lesser  pancreas  adheres  to  the 
duodenum,  and  when  it  is  enlarged  by  disease,  the  pas- 
sage of  aliment  through  that  intestine  is  much  impeded, 
and  sometimes  completely  obstructed.* 

It  is  now  generally  believed  that  the  fluid  secreted  by 
the  pancreas  is  similar  to  that  which  is  produced  by  the 
salivary  glands. 


SECTION  III. 

Of  the  Spleen. 

THE  Spleen  is  a flat  body  of  a blueish  colour,  and  an 
irregular  oblong  form,  with  thick  edges,  which  are  indent- 
ed in  some  places. 

It  is  various,  in  different  subjects,  both  in  size  and 
form.  Its  most  common  size  is  between  four  and  five 
inches  in  length,  and  about  three  or  four  inches  in  breadth; 
but  it  has  often  been  found  of  more  than  four  times  this 
size;  and  it  has  also  been  seen  not  much  longer  than  an 
inch.  Its  ordinary  weight  is  between  six  and  nine  ounces; 
but  it  has  varied  in  different  subjects  from  eleven  pounds 
to  one  ounce.  It  is  supposed,  by  many  physiologists,  that 
it  frequently  varies  in  size  in  the  same  individual. 

It  is  situated  in  the  left  hypochondriac  region,  in  con- 

* In  several  cases  where  examination  after  death  evinced  that  the 
pancreas  had  become  enlarged  and  indurated,  particularly  at  the  right 
extremity,  the  principal  symptoms  were  jaundice;  great  uneasiness 
after  taking  food;  vomiting  some  time  after  eating , but  not  immediately; 
extreme  acidity  of  the  matter  rejected. 


142 


Enlargement  of  the  Spleen. 

tact  with  the  diaphragm,  below  the  eighth  rib.  The  posi- 
tion of  the  spleen  is  somewhat  oblique, — one  extremity- 
being  directed  downwards  and  rather  forwards,  and  the 
other  upwards  and  backwards;  but  when  the  stomach  is 
distended,  the  lowrer  end  of  it  is  pushed  forward  by  the 
great  extremity  of  that  viscus. 

In  general  it  is  so  deeply  seated  in  the  left  hypochon- 
driac region,  that  it  is  out  of  view  when  the  subject  is 
opened  in  the  ordinary  way:  but  in  some  cases  of  enlarg- 
ment,  after  the  intermitting  fever,  it  has  extended  down- 
wards, nearly  as  low  as  the  pelvis;  and  towards  the  right 
side,  beyond  the  umbilicus. 

The  external  surface  of  the  spleen  is  convex,  in  confor- 
mity to  the  surface  of  the  diaphragm,  with  which  it  is  in 
contact.  The  internal  surface  of  the  spleen  is  irregularly 
concave,  having  a longitudinal  fissure  which  divides  it 
into  two  portions. 

The  spleen  is  invested  by  the  peritoneum,  one  process 
of  which  is  often  extended  from  the  diaphragm,  above 
and  behind  it,  in  the  form  of  ligament.  Another  process 
of  the  same  membrane  is  extended  to  it  from  the  great 
extremity  of  the  stomach.  The  peritoneum  is  also  con- 
tinued from  the  spleen  in  the  form  of  omentum. 

Within  this  peritoneal  covering  is  the  proper  coat  of 
the  spleen,  which  is  so  closely  connected  to  it,  that  many 
anatomists  have  considered  them  as  one  membrane:  they* 
are,  however,  very  distinct  at  the  great  fissure,  but  the 
external  coat  is  extremely  thin. 

The  proper  coat  of  the  spleen  is  not  very  thick;  it  is 
dense  and  firm,  and  somewhat  elastic,  but  not  much  so.  It 
is  partly  transparent. 

The  spleen  has  a large  artery,  which  is  one  of  the  three 
great  branches  of  the  cceliac.  This  vessel  runs  in  an  undu- 
lating manner  in  a groove  in  the  upper  edge  of  the  pan- 
creas, and  in  this  course  sends  off  many  small  branches 
to  supply  that  gland.  The  splenic  artery,  before  it  arrives 


143 


V essels  of  the  Spleen. 

at  the  spleen,  divides  into  five  or  six  branches,  which  are 
also  undulating  in  their  progress,  and  penetrate  into  the 
body  of  the  viscus  at  the  above  mentioned  fissure.  These 
branches  are  distributed  to  every  part  of  the  viscus,  and 
ramify  minutely. 

From  these  branches,  or  from  the  main  trunk  before  it 
ramifies,  three  or  four  smaller  branches  proceed  to  the  left 
extremity  of  the  stomach.  They  are  called  vasa  breviaor 
arteriac  breves. 

The  arteries  which  enter  the  spleen  are  accompanied 
by  veins  that  emerge  from  it,  and  unite  to  form  a great 
trunk.  This  trunk  observes  a course  corresponding  to  that 
of  the  splenic  artery,  and  receives  veins  from  the  stomach 
and  pancreas,  which  correspond  with  the  arterial  branches 
sent  to  those  organs.  The  splenic  vein  is  one  of  the  prin- 
cipal branches  of  the  vena  portarum. 

The  splenic  artery  is  very  large  in  proportion  to  the 
viscus  to  which  it  is  sent,  and  the  vein  is  unusually  large 
in  proportion  to  the  artery.  The  vein  is  also  very  tender 
and  delicate  in  its  structure. 

The  absorbent  vessels  of  the  spleen  are  very  numer- 
ous. It  has  been  asserted,  that  when  those  of  the  external 
coat  of  the  spleen  are  injected,  they  are  sufficient  to 
form  a fine  network  on  it.  The  absorbents  of  the  deep- 
seated  parts  unite  to  the  superficial  at  the  fissure  where 
the  bloodvessels  enter.  They  terminate  in  the  thoracic 
duct,  after  passing  through  several  lymphatic  glands. 

The  nerves  of  the  spleen  are  derived  from  the  solar 
plexus:  they  form  a plexus  round  the  vessels,  and  ac- 
company them  through  the  viscus. 

The  spleen  consists  of  a substance  which  is  much 
softer  than  that  of  any  other  viscus  of  the  abdomen. 
This  substance  is  made  up  either  wholly  or  in  great  part 
of  the  ramifications  of  the  splenic  artery  and  vein,  which 
are  demonstrated  by  injections  to  be  very  minute  and 
numerous  in  this  body.  There  are  also  many  fine  white 


144  Malpighi  on  the  Structure  of  the  Spleen. 

cords,  like  threads,  which  pass  from  the  internal  surface 
of  the  inner  coat  of  the  spleen  into  its  soft  substance,  in 
which  some  of  them  ramify.  These  cords  connect  the 
substance  of  the  spleen  pretty  firmly  to  its  coat,  and  they 
seem  to  have  the  effect  of  rendering  the  exterior  part  of 
the  substance  more  firm  and  dense  than  the  internal. 
They  are  particularly  conspicuous  if  the  spleen  be  im- 
mersed in  water,  and  the  coat  pulled  off  while  it  is  in  that 
situation. 

The  spleen  has  a strong  resemblance  to  the  glandular 
organs,  but  has  no  excretory  duct,  and  its  particular 
function  is  not  very  obvious:  for  these  reasons  the  struc- 
ture of  this  organ  is  a subject  of  very  interesting  inquiry. 

Malpighi,  who  took  the  lead  in  researches  of  this  na- 
ture, before  injections  of  the  bloodvessels  with  wax  were 
in  use,  after  investigating  the  structure  of  the  spleen  by 
long  maceration,  by  boiling,  by  inflation,  by  the  injection 
of  ink  or  coloured  fluids,  and  by  examination  with  mi- 
croscopes, declared  that  its  structure  was  cellular;  that 
the  cells  communicated  more  freely  with  the  veins  than 
the  arteries;  and  that  they  might  be  considered  as  appen- 
dices of  the  veins.  He  also  asserted,  that  a large  number 
of  white  bodies  or  vesicles  were  to  be  found  in  those 
cells,  and  throughout  the  whole  substance  of  the  spleen, 
which  were  in  bunches  like  grapes,  and  preserved  their 
whitish  colour  although  the  vessels  around  them  were 
injected  with  a coloured  fluid.  This  description  of  Mal- 
pighi appears  to  have  been  admitted  by  some  of  the  very 
respectable  anatomists  who  were  cotemporary  with  him; 
but  it  was  most  zealously  opposed  by  Ruysch,  who  ex- 
hibited the  spleen  so  completely  injected  with  wax,  that 
it  appeared  to  be  composed  entirely  of  vessels.* 

* Two  plates,  taken  from  drawings  of  these  preparations,  are  pub- 
lished in  Ruysch’s  works.  One  is  attached  to  Epistola  Problematica 
Quarta,  in  the  second  volume;  and  the  other  to  Thesaurus  Septimus, 
in  the  third  volume. 


145 


Be  La  Some  on  the  Spleen. 

Ruysch  appears  to  have  paid  great  attention  to  this 
subject,  and  to  have  made  many  preparations  of  the 
spleen.  From  these  he  derived  the  opinion,  that  the  sub- 
stance of  this  organ  was  entirely  composed  of  arteries, 
veins,  absorbent  vessels  and  nerves;  and  that  if  it  were 
properly  injected  before  it  was  dissected,  no  other  struc- 
ture would  be  found.  He  stated,  that  the  minute  ramifi- 
cations of  the  bloodvessels  appeared  to  have  acquired  a 
peculiar  quality,  and  were  so  soft  and  delicate,  that  their 
texture  was  destroyed  by  the  least  friction;  and  that  by 
the  slightest  degree  of  putrefaction  they  appeared  to  be 
reduced  to  a fluid  state.  He  also  denied  the  existence  of 
cells,  or  of  the  whitish  bodies  described  by  Malpighi. 

The  question  thus  at  issue  between  these  great  masters 
of  their  art,  was  very  carefully  examined  by'  M.  De  La 
Sone,  a French  physician,  whose  observations  are  pub- 
lished in  the  Memoirs  of  the  Academy  of  Sciences  for 
1754.  After  repeating  the  processes  of  each  of  these 
anatomists,  and  instituting  some  others  in  addition,  he 
adopted  the  opinion  that  there  was  in  the  texture  of  the 
spleen  a pulpy  substance  which  was  not  a mere  coagu- 
lum,  but  which,  however,  could  not  be  injected. 

He  derived  his  opinion  from  this  fact  among  others. 
After  macerating  the  spleen  a considerable  time,  and  in- 
jecting water  into  the  vessels  until  it  returned  colourless, 
he  injected  ink,  and  confined  it  some  time  in  the  vessels 
by  tying  them;  he  then  allowed  the  ink  to  flow  out  of  the 
vessels,  and  made  various  sections  of  the  spleen,  but  no 
ink  appeared  in  the  pulpy  substance,  although  it  was 
visible  in  many  small  vessels  which  ramified  in  that  sub- 
stance. He  ‘observes  that  this  could  not  have  been  the 
case,  if  the  pulpy  substance  had  been  composed  entirely 
of  vessels,  as  was  supposed  by  Ruysch. 

He  also  examined  the  spleen  after  it  had  been  injected 
with  wax,  according  to  the  manner  of  Ruysch,  and  be- 
lieved not  only  that  the  pulpy  matter  remained  uninject- 
Vol,  II.  T 


146  Haller  and  the  French  Anatomists  on  the  Spleen . 

ed,  but  that  Ruysch  himself,  in  his  own  preparations, 
removed  this  substance,  supposing  it  to  exist  for  the 
mere  purpose  of  connecting  the  vessels  to  each  other. 

To  see  the  bloodvessels  in  the  same  state  of  distention 
in  which  they  were  during  life,  he  tied  the  splenic  ves- 
sels in  a living  animal,  and  removed  the  spleen  with  the 
ligatures  on  the  vessels.  In  this  situation  he  boiled  it, 
and  then  examined  the  appearance  of  the  vessels  and  the 
pulpy  substance.  From  these,  as  well  as  his  other  obser- 
vations, he  decided,  that  the  pulpy  substance  did  not 
consist  entirely  of  vessels,  but  was  an  additional  and  dif- 
ferent structure. 

He  also  suggested,  that  as  the  brain  and  the  muscular 
fibres  were  so  covered  by  bloodvessels  in  the  injected 
preparations  of  Ruysch,  that  they  appeared  to  be  com- 
posed entirely  of  vessels,  when  in  fact  they  consisted 
of  a different  substance,  so  the  pulpy  substance  of  the 
spleen  was  covered  or  obscured  by  the  bloodvessels 
which  passed  through  it,  without  constituting  its  whole 
substance. 

He  confirms  the  account  of  Malpighi  respecting  the 
Whitish  Vesicles  or  Follicles;  and  states,  that  in  a ma- 
jority of  cases  they  are  not  to  be  discovered  without  a 
particular  preparation;  but  that  they  are  generally  made 
obvious  by  long  maceration  of  the  spleen  in  water.  In 
his  opinion  they  are  the  most  essential  part  of  the  organ. 

Notwithstanding  these  investigations  of  M.  De  La 
Sone,  the  question  respecting  the  structure  of  the  spleen 
remains  not  completely  decided  even  to  this  day. 

Haller,  who  was  perfectly  well  acquainted  with  the  sub- 
ject, inclined  to  the  opinion  of  Ruysch;  while  Sabatier 
adopted  completely  the  opinion  of  De  La  Sone. 

It  appears  from  the  statement  of  Gavard,  that  Desault 
did  not  at  mit  the  existence  of  the  transparent  bodies;  al- 
though hi  elieved  that  the  pulpy  substance  of  the  spleen 


147 


British  Anatomists  on  the  Spleen. 

Consisted  of  cells  which  resembled  those  of  the  cavernous 
bodies  of  the  penis. 

Boyer,  whose  descriptions  of  the  animal  structure  ap- 
pear to  have  been  formed  with  scrupulous  exactitude, 
admits  the  existence  of  transparent  bodies;  sometimes  so 
small  as  to  be  scarcely  visible,  and  sometimes  as  large  as 
the  head  of  a pin.  He  observes,  that  the  best  method  of 
examining  them  is  to  place  a very  thin  slice  of  the  spleen 
between  the  eye  and  a strong  light,  when  the  transpa- 
rency of  these  bodies  occasions  the  slice  of  the  spleen  to 
appear  as  if  perforated. 

As  to  the  general  structure  of  the  pulpy  substance,  he 
avows  himself  unable  to  decide  respecting  it;  but  ob- 
serves, that  upon  examining  the  cut  surface  of  the  spleen, 
you  perceive  black  liquid  blood  flow  from  the  vessels;  if 
you  then  scrape  this  surface,  you  may  express  easily  a 
species  of  sanies  different  from  that  which  flows  from  the 
vessels,  which,  after  exposure,  becomes  red,  and  resem- 
bles coagulated  blood:  whether  this  is  contained  in  the 
capillary  vessels,  or  in  the  cavities  of  this  organ,  he  ac- 
knowledges himself  unable  to  determine. 

Notwithstanding  the  sentiments  of  these  French  gen- 
tlemen, many  of  the  British  Anatomists,  who  are  entitled 
to  great  attention  on  account  of  their  skill  in  minute  in- 
jections, have  adopted  the  ideas  of  Ruysch.  Among  these 
are  to  be  mentioned  the  late  Dr.  F.  Nicholls,  and  many 
of  the  anatomists  of  London,  as  well  as  the  second  Pro- 
fessor Monro,  of  Edinburgh.  There  are,  however,  two 
remarkable  exceptions  to  this  account  of  the  British  Ana- 
tomists. The  late  Mr.  Falconar,  who  wrote  a dissertation 
on  the  situation  and  structure  of  the  spleen,  which  con- 
tains the  sentiments  of  the  late  truly  respectable  Mr.  Hew- 
son,*  after  stating  that  the  organ  was  extremely  vascular, 
so  that  when  injected  it  appeared  like  a mere  congeries  of 

* See  Experimental  Inquiries,  vol^  III, 


148 


Questions  relating  to  the 

vessels,  makes  this  unequivocal  assertion, — that  there  are 
innumerable,  cells  dispersed  throughout  the  whole  sub- 
stance of  it,  which  are  so  small  that  they  are  only  to  he 
discovered  by  the  aid  of  a microscope ; and  are  to  be  seen 
after  steeping  a thin  piece  of  spleen,  the  bloodvessels  of 
which  have  been  minutely  injected,  in  clear  water  during 
a day,  and  changing  the  water  frequently.  He  also  adds, 
that  the  ultimate  branches  of  the  arteries  and  veins  form 
a beautiful  network  on  each  cell;  and  that  these  cells  are 
sufficiently  distinguished  from  the  irregular  interstices  of 
the  cellular  substance,  by  their  round  figure  and  their 
great  regularity. 

Mr.  Everard  Home,  in  his  papers  on  the  structure  and 
uses  of  the  spleen,  confirms  the  account  of  the  vesicles  in 
this  organ;  and  adds,  that  these  vesicles  are  occasionally 
seen  in  a distended  and  in  a contracted  state.  That  when 
distended  they  are  twice  as  large  as  when  contracted,  and 
are  distinguishable  by  the  naked  eye;  whereas,  when  con- 
tracted, they  require  a magnifying  glass  to  be  distinctly 
seen.  These  observations  appear  to  have  been  made  upon 
quadrupeds.* 

Professor  Soemmering  appears  to  unite  in  the  general 
sentiment  of  the  British  anatomists,  that  the  spleen  is  sim- 
ply vascular.  He  says,  that  the  tuberculi  which  sometimes 
appear  in  it,  when  examined  with  a magnifying  glass,  ap- 
pear to  be  composed  entirely  of  vessels. 

There  are  therefore  two  questions  not  perfectly  decid- 
ed respecting  the  spleen. 

First.  Whether  its  general  structure  is  simply  vascular, 
or  whether  there  is  airy  other  structure,  either  cellular  or 
more  substantial,  which  composes  its  general  bulk. 

Second.  Whether  the  small  transparent  vesicles,  ori- 
ginally described  by  Malpighi,  are  to  be  regarded  as  es- 
sential parts  of  the  structure  of  the  spleen. 

*See  the  London  Philosophical  Transactions  for  1808. 


149 


Structure  of  the  Spleen. 

With  respect  to  the  first  question,  the  injections  of 
Ruysch,  and  of  the  British  Anatomists  in  general,  and 
even  of  Mr.  Hewson,  as  well  as  of  Haller  and  Soemmer- 
ing, seem  to  afford  positive  facts  in  opposition  to  those  of 
a negative  kind  adduced  by  M.  De  La  Sone,  and  render 
it  highly  probable  that  the  general  structure  is  simply 
vascular. 

But  the  second  question  stands  on  different  grounds. 
The  existence  of  small  transparent  vesicles,  although  de- 
nied by  Ruysch,  and  neglected  by  the  British  Anatomists 
in  general,  was  asserted  as  a positive  fact  by  Malpighi  and 
De  La  Sone;  and  their  assertions  have  been  confirmed, 
not  only  by  most  of  the  French  Anatomists,  but  also  by 
Hewson  and  Home  among  the  British. 

The  sentiments  of  physiologists  respecting  the  func- 
tions of  the  spleen,  are  more  discordant  than  those  of 
anatomists  respecting  its  structure;  although  the  subject 
has  been  considered  by  many  authors  of  great  ingenuity.* 

*See  M,  Lieutaud.  Elementa  Physiologise. 

Hewson’s  Experimental  Inquires,  vol.  III. 

Dr.  Rush  Medical  Museum,  vol.  III. 

Haller.  Elementa  Physiologise,  tom.  vi.  pag.  414. 


150 


CHAPTER  IY. 

iOF  THE  URINARY  ORGANS,  AND  THE  GLANDULJE  RENALES. 

THE  urinary  organs  consist  of  the  Kidneys , which  are 
situated  in  the  lumbar  regions;  of  the  Bladder , which  is  in 
the  pelvis;  of  the  Ureters , which  are  flexible  tubes  or  ca- 
nals that  pass  from  the  kidneys  to  the  bladder;  and  of  the 
Urethra , or  tube  through  which  the  urine  is  discharged 
from  the  bladder. 

These  organs  have  but  little  connexion  with  the  peri- 
toneum. The  kidneys  are  behind  it;  and  a considerable 
quantity  of  cellular  membrane  is  placed  between  them  and 
it.  The  ureters  are  also  behind  it;  and  but  a part  of  the 
bladder  is  invested  with  it. 

The  Glandules  Renales  are  described  with  the  urinary 
organs,  on  account  of  their  contiguity  to  the  kidneys;  and 
to  avoid  a derangement  of  the  natural  order  of  descrip- 
tion they  are  considered  first. 

The  urethra  pertains  to  the  organs  of  generation  as  well 
as  to  the  urinary  organs,  and  can  be  described  most  ad- 
vantageously with  them. 


SECTION  I. 

Of  the  Glandules  Renales. 

THESE  are  two  small  bodies,  situated  on  the  psoas 
muscle,  one  on  each  side  of  the  spine,  behind  the  peri- 
toneum and  above  the  kidney,  being  in  contact  with  its 
upper  and  anterior  edge.  They  have  an  irregular  se- 


Glandules  JRenales. 


151 


milunar  figure  with  three  sides,  one  of  which  is  accom- 
modated to  the  convexity  of  the  kidney.  Their  colour  is 
commonly  a dull  yellow. 

The  appearance  and  texture  of  these  bodies  have  some 
resemblance  to  those  of  glands,  and  hence  their  name; 
but  they  have  no  excretory  duct. 

When  they  are  laid  open  by  an  incision,  a cavity  often 
appears,  which  is  somewhat  triangular,  and  from  the 
lower  part  of  it  a small  thin  ridge  arises.* 

A small  quantity  of  fluid  is  generally  found  in  it,  which 
has  a very  dark  colour  in  adults,  is  yellowish  in  young 
subjects,  and  red  in  infants. 

These  bodies  have  not  a single  artery  appropriated  to 
them,  as  the  spleen  has,  but  receive  small  branches  from 
several  contiguous  sources;  viz.  from  the  arteries  of  the 
diaphragm,  from  the  coeliac  artery  or  the  aorta,  and  from 
the  arteries  of  the  kidneys.  There  is  generally  one  prin- 
cipal vein,  as  well  as  some  that  are  smaller,  belonging  to 
each  of  these  bodies:  the  large  vein  on  the  right  side  ge- 
nerally opens  into  the  vena  cava,  and  on  the  left  into  the 
left  emulgent  vein. 

These  bodies  were  first  described  by  Eustachius,  and 
have  been  regarded  with  attention  by  many  anatomists 
since  that  period.  They  exist  in  a great  number  of  ani- 
mals; but  their  nature  and  functions  are  altogether  un- 
known. 

* The  cavity  in  these  bodies  has  sometimes  been  sought  for  in 
vain.  Haller  found  it  in  sixteen  cases  out-  of  nineteen. 


152 


SECTION  II. 

Of  the  Kidneys  and  Ureters . 

THE  kidneys  are  two  glandular  bodies  which  secrete 
the  urine.  They  are  of  a dull  red  colour,  and  their  from 
has  a strong  resemblance  to  that  of  the  bean  which  bears 
their  name.  They  have  a peculiar  texture,  which  is  uni- 
form, and  not  granulated  or  composed  of  acini;  and  they 
are  covered  by  a thin  delicate  tunic,  which  has  no  con- 
nection with  the  peritoneum. 

They  are  situated  in  the  lumbar  regions  of  the  abdo- 
men, one  on  each  side  of  the  spine.  They  are  opposite  to 
the  two  last  dorsal  and  the  two  first  lumbar  vertebras. 
They  rest  principally  upon  the  psoas  and  the  quadratus 
lumborum  muscles,  and  their  position  is  oblique;  the 
concave  edge  presenting  inwards  and  forwards,  the  con- 
vex edge  backwards,  and  the  upper  extremity  approach- 
ing nearer  to  the  spine  than  the  lower. 

The  Right  Kidney  is  situated  rather  lower  than  the 
left:  it  is  below  the  posterior  part  of  the  right  lobe  of  the 
liver,  and  behind  the  duodenum  and  the  colon.  The  Left 
Kidney  is  below  the  spleen,  and  behind  the  descending 
portion  of  the  colon.  Each  of  the  kidneys  is  below  and 
very  near  to  one  of  the  glandulae  renales. 

They  arc  surrounded  with  a large  quantity  of  lax  adi- 
pose membrane,  which  in  corpulent  persons  forms  a very 
large  mass  of  adeps  around  them;  while  in  the  emaciated 
they  are  surrounded  with  a membrane  almost  free  from 
fat.  Each  kidney  has  two  broad  sides,  two  extremities, 
and  two  edges.  The  side  or  surface  which  is  posterior, 
when  the  kidney  is  in  its  natural  situation,  is  rather 
broader  than  the  other.  The  upper  extremity,  or  portion, 
is  also  broader  and  larger  than  the  lower.  The  edge 
which  is  posterior  and  external  is  regularly  convex;  the 


153 


The  Kidneys. 

anterior  edge  is  concave;  but  the  concave  edge,  or  mar* 
gin,  is  not  very  regular.  In  the  middle  it  is  largely  in- 
dented; in  this  indentation  is  a deep  fissure,  which  sepa- 
rates the  two  broad  surfaces  or  sides  of  the  gland  from 
each  other;  and  here  the  breadth  of  the  posterior  surface 
is  evidently  greater  than  the  anterior. 

Each  of  the  kidneys  receives  a large  artery,  which 
proceeds  immediately  from  the  aorta,  nearly  in  a rectan- 
gular direction.  A vein,  which  opens  into  the  vena  cava, 
accompanies  the  artery.  It  is  obvious,  from  the  situation 
of  the  kidneys  with  respect  to  the  great  vessels,  that  the 
artery  on  the  right  side  must  be  longer  than  that  on  the 
left,  and  that  the  reverse  of  this  must  be  the  case  with 
the  veins:  the  veins  are  also  anterior  to  the  arteries.  At 
the  great  fissure  these  vessels  divide  into  several  branch- 
es, which  enter  the  kidney  at  that  place.  The  branches 
of  the  vein  are  before  and  above;  those  of  the  artery  are 
below,  and  in  the  middle.  Surrounded  more  or  less  by 
the  branches  of  those  vessels,  is  a membranous  sac,  the 
breadth  of  which  extends  from  above  downwards.  This 
sac  terminates  in  a tube  that  proceeds  from  the  lower 
part  of  the  fissure  down  to  the  bladder.  The  sac  is  deno- 
minated the  pelvis  of  the  kidney,  and  the  tube  a ureter; 
each  of  these  parts  will  soon  be  more  particularly  de- 
scribed. 

The  substance  of  the  kidney,  as  has  been  already  said, 
is  uniform  in  its  texture,  and  of  a reddish  brown  colour. 
When  it  is  divided  by  an  incision  made  lengthways,  and 
from  its  convex  to  its  concave  edge,  there  appears  to  be 
a small  difference  in  the  different  parts  of  it.  The  exte- 
rior part,  which  is  called  cortical,  is  rather  more  pale  in 
colour  and  softer  in  consistence  than  the  internal  part.  It 
varies  in  thickness,  so  that  some  writers  have  described 
it  as  equal  to  two  lines,  and  others  to  one  third  of  the 
kidney.  In  a majority  of  subjects  it  will  be  found  be- 
tween the  two  statements. 

Vol.  II. 


U 


154 


The  Kidneys . 

The  interior  part  is  called  medullary,  or  tubular,  and 
appears  to  be  composed  of  very  fine  tubes.  These  tubes 
are  so  arranged,  that  a number  of  papillae  or  cones  are 
formed  by  their  convergence,  and  project  into  the  fissure 
of  the  kidney.  These  papillae  have  been  supposed  to  con- 
sist of  a substance  different  from  either  of  the  two  above 
mentioned,  but  they  appear  to  be  formed  merely  by  the 
tubular  part. 

The  arteries,  accompanied  by  corresponding  veins, 
and  by  nerves  and  absorbent  vessels,  after  ramifying  in 
the  fissure  of  the  kidney,  proceed  into  its  substance,  and 
continue  their  aborescent  ramifications  until  they  have 
arrived  very  near  the  exterior  surface.  They  are  so  uni- 
formly distributed  to  the  different  parts  of  the  organ,  that 
when  the  bloodvessels  are  injected  with  wax,  and  the 
substance  of  the  kidney  is  removed  from  the  injected 
matter,  as  is  the  case  in  corroded  preparations,  the  injec- 
tion exhibits  accurately  the  form  of  the  kidney. 

The  large  branches  of  the  bloodvessels  occupy  the  va- 
cuities between  the  papillae  in  the  fissure  of  the  kidney. 
When  they  penetrate  the  substance  of  the  kidney,  they 
are  inclosed  by  sheaths  which  are  derived  from  the  coat 
of  the  gland,  and  are  surrounded  by  membrane,  which 
frequently  contains  adeps. 

There  are  commonty  ten  or  twelve  papillae  in  the  fis- 
sure of  each  kidney,  but  there  are  sometimes  more  and 
sometimes  less  than  this  number.  These  papillae  are  sur- 
rounded by  a membranous  sac  of  a corresponding  form; 
the  papilla  being  a cone,  and  the  sac  resembling  the  upper 
part  of  a funnel.  The  sac  is  therefore  called  an  infundi- 
bulum, or  calyx.  Sometimes  there  are  two  papillae  in 
each  infundibulum,  and  then  the  form  of  the  sac  is  not 
so  regular.  The  infundibulum  adheres  to  the  base  of  the 
papilla,  but  lies  loose  about  the  other  parts  of  it.  Each 
infundibulum  communicates,  at  its  apex,  with  the  pelvis 
of  the  kidney. 


Cortical  and  Tubular  Portions  of  the  Kidney.  155 

The  Pelvis , as  has  been  already  mentioned,  is  a mem- 
branous sac  which  terminates  in  the  ureter,  exterior  to  the 
kidney.  This  sac  generally  divides  itself,  in  the  fissure  of 
the  kidney,  into  three  large  irregular  branches,  each  of 
which  very  soon  terminates  in  three  or  four  of  the  infun- 
dibula above  described.  That  portion  of  the  sac  which 
terminates  in  the  ureter,  is  exterior  to  the  kidney. 

When  the  interior  parts  of  the  kidney  are  exposed  to 
view,  by  the  section  above  mentioned,  after  the  arteries 
and  veins  have  been  minutely  injected,  the  cortical  part 
will  be  found  to  consist  almost  entirely  of  the  minute 
ramifications  of  these  vessels.  Among  them  are  some 
small  bodies,  which  are  dispersed  through  the  substance, 
like  berries  on  a bush:  these  are  asserted  also  to  be  com- 
posed of  vessels. 

The  tubular  part  certainly  proceeds  from  this  vascular 
cortical  substance:  for  Ruysch,  and  after  him  several 
other  injectors,  have  filled  these  tubes  with  injection 
thrown  into  the  arteries. 

The  tubuli  of  which  this  part  is  composed,  seem  to 
arise  obscurely  from  the  cortical  part.  They  soon  assume 
somewhat  of  a radiated  direction,  and  are  finally  arranged 
so  as  to  form  the  papillae  or  cones  above  described. 

On  these  papillae  or  cones  some  of  them  can  be  traced, 
uniting  with  each  other,  to  form  larger  tubes,  which  ter- 
minate on  the  surfaces  of  the  papillae,  in  orifices  large 
enough  to  be  seen  distinctly.  From  these  orifices  urine 
may  be  forced  out,  by  compressing  the  papillae.  On  this 
account  the  tubes  have  been  called  tubuli  uriniferi. 

In  the  foetal  state  the  kidney  is  formed  of  a number  of 
distinct  lobuli,  each  of  which  consists  of  a papilla  with  the 
cortical  matter  connected  to  its  base.  Soon  after  birth 
these  lobuli  coalesce;  and  in  two  or  three  years  the  sub- 
stance of  the  kidney  appears  uniform,  as  above  described. 
In  some  animals  this  lobulated  structure  continues  during 
life:  in  them,  and  also  in  the  foetus,  each  lobe  appears  like 


156  Nerves  and  Lymphatics.  Coat  of  the  Kidney . 

a distinct  organ.  Although  in  the  adult  kidney  this  struc- 
ture has  disappeared,  the  papillae  and  the  tubular  part  con- 
nected with  them  are  somewhat  detached  from  each  other, 
in  a manner  corresponding  to  their  original  arrangement. 

The  Nerves  of  the  Kidneys  originate  from  the  semilunar 
ganglion,  formerly  mentioned.  They  form  a plexus  round 
the  bloodvessels,  and  go  with  them  into  the  gland. 

The  kidneys  have  internal  and  external  absorbent  ves- 
sels, although  the  external  vessels  are  very  small.  These 
absorbents  pass  through  glands  in  the  lumbar  region  to 
the  thoracic  duct. 

The  proper  coat  of  the  kidney  is  said,  by  some  anato- 
mists, to  consist  of  two  laminae;  but  this  cannot  be  shown 
in  common  cases.  It  appears  simple  in  its  structure,  and 
very  flexible.  It  is  but  slightly  connected  to  the  glandular 
substance  which  it  incloses,  and  may  be  easily  peeled  off. 
It  is  reflected  inwards  at  the  fissure  of  the  kidney,  and 
can  be  traced  inwardly  to  some  distance,  forming  sheaths 
for  the  vessels.  In  this  internal  situation  it  is  very  thin. 

The  Ureters. 

The  pelvis  of  the  kidney  terminates  exteriorly  in  the 
Ureter , which  is  a membranous  cylindrical  tube,  rather 
flattened,  and  between  three  and  five  lines  in  diameter, 
with  some  variations  in  this  respect. 

The  Ureters  descend  from  the  pelvis  of  the  kidney  so 
as  to  pass  obliquely  across  the  psoas  muscle  and  the 
great  iliac  vessels.  They  are  behind  the  peritoneum, 
but  in  contact  with  it.  They  approach  the  pelvis  near 
the  junction  of  the  os  ileum  with  the  sacrum,  and  thence 
descend  forwards  and  inwards,  surrounded  with  loose 
cellular  membrane,  to  the  lower  part  of  the  bladder,  into 
which  they  are  inserted  at  its  external  and  posterior  part. 
They  first  penetrate  obliquely  the  muscular  coat,  and  then 
proceed  between  the  muscular  and  internal  coats,  from 


157 


Structure  of  the  Ureters. 

half  an  inch  to  an  inch,  in  an  oblique  direction,  from  with- 
out inwards  and  forwards,  when  they  terminate  by  small 
orifices  in  the  internal  coat,  each  of  which  is  at  an  equal 
distance  (rather  more  than  an  inch)  from  the  orifice  of  the 
urethra,  thus  forming  a triangle  with  it. 

The  ureters  are  said  to  have  three  coats.  The  exterior 
appears  to  be  derived  from  the  cellular  substance:  within 
it  is  another,  which  has  been  regarded  very  differently  by 
different  anatomists;  some  considering  it  as  merely  mem- 
branous, and  others  as  muscular.  If  the  ureter  be  laid 
open,  and  the  internal  coat  peeled  off,  the  muscular  struc- 
ture of  this  coat  is  often  very  perceptible. 

The  internal  coat  is  called  villous,  or  mucous,  and  is 
continued  from  the  internal  coat  of  the  bladder.  Over  this 
coat  mucus  is  constantly  spread,  which  defends  it  from 
the  acrimony  of  the  urine.  It  is  very  difficult  to  separate 
the  two  last  mentioned  coats  from  each  other. 

The  ureters  receive  bloodvessels  and  nerves  from  those 
of  the  neighbouring  parts.  Their  internal  coat  is  very  vas- 
cular, and  is  also  very  sensible  of  irritation.  The  passage 
of  a small  urinary  calculus  can  be  traced  from  the  pelvis 
of  the  kidney  to  the  bladder,  by  the  exquisite  pain  and 
the  spasmodic  affections  which  it  often  excites. 


SECTION  III. 

Of  the  Urinary  Bladder . 

THE  urinary  bladder  is  a large  sac,  of  a muscular  and 
membranous  structure,  which  occupies  the  anterior  part 
of  the  cavity  of  the  pelvis,  immediately  within  the  ossa 
pubis. 

The  size  of  the  bladder  is  in  a continued  state  of  varia- 
tion, according  to  the  quantity  of  urine  secreted.  When 


158  Situation  of  the  Bladder. 

moderately  distended,  it  is  of  an  irregular  oval  form,  but 
rather  more  flat  at  its  lower  extremity  than  above.  It 
varies  in  form  according  to  the  different  circumstances  of 
the  pelvis  to  which  it  has  been  subjected. 

It  is  fixed  firmly  and  immoveably  to  the  pelvis,  imme- 
diately within  the  symphysis  pubis;  so  that  it  is  always  to 
be  found  there  of  a larger  or  smaller  size.  It  is  sometimes 
completely  empty,  and  occupies  no  more  space,,  than  the 
thickness  of  its  coats  requires.  When  moderately  distend- 
ed, it  occupies  a considerable  portion  of  the  pelvis:  when 
distention  increases,  it  presses  the  parts  posterior  to  it 
against  the  sacrum,  and  extends  itself  above  tffe  brim  of 
the  pelvis  into  the  general  cavity,  rising  not  only  to  the 
umbilicus,  but  in  some  cases  to  the  epigastric  region. 

In  males  the  relative  situation  of  the  bladder-  and  rec- 
tum is  such,  that  the  upper  and  middle  part  of  the  rectum 
is  behind  the  bladder;  but  the  lower  part  of  the  rectum, 
following  the  curve  of  the  os  sacrum  and  coccygis,  is  be- 
low the  posterior  part  of  the  bladder. 

In  females  the  vagina  and  uterus  are  situated  between 
the  bladder  and  rectum;  so  that  the  connexion  of  these 
last  mentioned  parts  is  very  different  in  the  two  sexes. 

The  peritoneum  is  reflected  at  the  anterior  part  of  the 
brim  of  the  pelvis  from  the  abdominal  muscles,  which  it 
lines,  to  the  upper  part  of  the  bladder,  which  is  generally 
contiguous  to  the  brim  of  the  pelvis.  It  continues  over  to 
the  posterior  side  of  the  bladder,  and  passes  down  upon  it 
some  distance  towards  the  lower  part;  but  before  it  has 
arrived  at  the  bottom,  it  is  reflected  towards  the  sacrum. 

In  males  it  extends  from  the  bladder  to  the  rectum,  and 
in  females  to  the  vagina*  and  uterus;  so^that.  there  is  a 
considerable  portion  of  the  lower  part  of  the  bladder 
which  is  not  invested  by  the  peritoneum.  It  also  follows 
that  when  the  bladder  is  extended  into  the  abdomen,  and 
rises  above  the  brim  of  the  pelvis,  that  part  of  it  which 
presents  anteriorly,  and  is  in  contact  with  the  abdominal 


Muscular  Coat  of  the  Bladder . 159 

muscles,  is  without  a covering  of  peritoneum,  being  be- 
low it. 

The  bladder  is  composed  of  a coat  consisting  of  mus- 
cular fibres,  of  a stratum  of  cellular  substance  immediately 
within  this,  and  of  an  internal  lining  membrane,  which  has 
been  called  villous,  but,  as  there  are  no  villi  preceptible 
on  it,  may  be  more  properly  denominated  mucous. 

It  should  be  observed,  that,  in  addition  to  these  coats, 
the  bladder  has  a peculiar  investment  of  the  peritoneum, 
as  has  been  already  described;  and  also  of  the  common 
cellular  membrane,  which  is  placed  between  it  and  every 
part  to  which  it  is  contiguous. 

The  Muscidar  Coat  of  the  Bladder  consists  of  fibres 
which  are  not  spread  over  it  of  a uniform  thickness,  but 
are  thin  in  some  places,  and  in  others  are  collected  in  fas- 
ciculi. They  run'®6very  direction:  some  appear  longitu- 
dinal, others  cirrml^r,  and  some  oblique;  and  there  are 
intersticq^between  them  which  are  occupied  by  cellular 
membrane.  The  longitudinal  fibres  originate  from  the 
lower  paft  of  the  bladder;  and  as  this  is  the  fixed  part  of 
that  visousph1  is  the  place  from  which  these  fibres  must 
necessarily  act.  These  fibres  are  generally  exterior.  There 
is  no  arrangement  of  muscular  fibres  to  which  the  term  of 
sphincter  can  properly  be  applied;  but  many  anatomists 
have  thought  .that  the  fibnes  near  the  neck  of  the  bladder, 
by  their  separate  contraction,  might  prevent  the  escape  of 
urine:  thi|_sentirhent,  however,  is  contrary  to  that'of  se- 
veral viery  respectable  writers.  M 

The  direction  of  the  fibres,  taken  collectively,  is  such® 
that,  when  they  all  contract,  the  cavity  of  the  bladder  is 
completely'obliterated. 

The  cellular  substance  between  the  muscular  and  inter- 
nal coats  is  dense.  It  yields  in  a remarkable  manner  to 
distention,  and  recovers  its  original  dimensions  very  easi- 
ly. From  its  analogy  to  a similar  coat  in  the  intestines, 
it  is  called  the  Nervous  Coat. 


160  Internal  Coat  of  the  Bladder. 

The  Internal  Coat  of  the  bladder  is  of  a light  colour  in 
the  dead  subject,  when  it  has  been  free  from  disease.  It 
has  been  called  villous  improperly;  for  the  villous  struc- 
ture is  not  apparent  upon  its  surface.  Being  continued 
from  the  integuments  of  the  body  which  are  extended 
along  the  urethra,  it  has  been  inferred,  that  the  surface  of 
this  coat  was  formed  by  the  epidermis;  and  some  respect- 
able authors  have  supposed  that  they  had  seen  cases  in 
which  portions  of  the  epidermis  of  the  bladder  had  sepa- 
rated and  been  discharged;  but  these  appearances  are  very 
equivocal,  and  it  is  by  no  means  certain  that  an  epidermis 
exists  there.* 

The  fasciculi  of  fibres  of  the  muscular  coat  occasion 
this  coat  to  appear  very  irregular,  but  these  irregularities 
correspond  exactly  with  the  arrangement  of  the  fibres  of 
the  muscular  coat. 

When  the  internal  coat  is  separated  by  dissection  from 
the  muscular,  its  surface  is  very  smooth  and  crt*iform.  In 
the  recent  subject,  when  no  disease  has  previously  existed, 
it  always  spread  over  with  mucus  of  a light  colour,  but 
nearly  transparent,  which  can  be  easily  scra’ffed  off.  This 
mucus  is  spread  upon  the  surface  so  uniformly,  that  it 
must  be  derived  from  sources  which  are  situated  upon 
every  part  of  the  surface;  but  these  sources  are  not  very 
obvious.  On  the  membrane  of  the  nose  the  orifices  of 
many  mucous  ducts  are  very  visible,  but  such  orifices  are 
not  to  be  seen  on  this  surface.  Haller  mentions  that  he  has 
seen  mucous  glands  near  the  neck  of  the  bladder;  and  it 
is  stated  by  the  pupils  of  Desault,  that,  in  one  of  his 
courses,  he  pointed  out  a number  of  these  glands,  in  a 
subject  who  had  been  afflicted  with  a catarrhal  affection 
of  the  bladder. 

* In  the  fauces  and  the  follicles  of  the  tonsils  an  effusion  of  coagu- 
lable  matter,  in  consequence  of  inflammation,  often  forms  crusts,  that 
may  be  mistaken  for  sloughs  of  the  integuments,  although  those  inte- 
guments remain  entire. 


161 


Mucus  of  the  Bladder. 

Notwithstanding  that  the  sources  of  this  mucus  are  ob- 
scure, the  quantity  of  it  is  sometimes  immense.  In  some 
cases,  where  the  secretion  is  increased  by  the  irritation  of 
a calculus  in  the  bladder,  the  urine  is  rendered  somewhat 
viscid  and  white  coloured  by  the  mucus  mixed  with  it; 
which,  after  the  urine  has  been  allowed  to  remain  for 
some  time,  subsides  in  such  quantities  as  demonstrates 
that  many  ounces  must  be  secreted  in  the  course  of  the 
twenty-four  hours.  The  same  circumstances  occur,  with- 
out the  irritation  of  calculus,  in  the  disease  called  catar* 
rhus  vesicas.* 

It  is  probable  that,  in.  healthy  persons,  a great  deal  of 
it  passes  off  unperceived,  being  dissolved  or  diffused  in  the 
urine.  From  the  quantity  and  the  regular  diffusion  of  this 
mucus  on  the  surface  of  the  bladder,  there  is  the  greatest 
reason  for  believing  that  it  is  effused  from  every  part  of 
the  surface;  and  it  is  a question  that  has  not  b en  decided, 
whether  it  is  discharged  from  glandular  ducts  too  small 
to  be  perceived,  or  from  the  exhalent  extremities  of  the 
bloodvessels.  It  is  probable  that  the  use  of  it  is  to  defend 
the  internal  coat  of  the  bladder  from  the  acrimony  of  the 
urine. 

The  symptoms  of  a stone  in  the  bladder,  as  well  as  of 
several  other  diseases,  evince  that  this  coat  is  endued  with 
a great  degree  of  sensibility. 

It  is  evident  that  the  essential  parts  in  the  general 
structure  of  the  bladder  are  the  muscular  coat  and  the 
internal  coat  last  described:  but  in  addition  to  the  account 
of  them,  there  are  some  other  important  circumstances  to 
be  noted  in  the  description  of  this  organ.  It  has  been 
already  stated,  that  the  form  of  the  bladder  was  an  irregu- 
lar oval,  although  it  was  somewhat  varied  in  different 

* In  some  cases  this  mucus  soon  becomes  putrid,  and  during  the 
putrefactive  process  deposits  a substance  which  appears  to  be  calca- 
reous. 

VOL.  II. 


X 


162 


Orifice  of  the  Urethra . 

persons.  The  oval  form  is  not  much  altered  at  the  part 
called  the  neck  of  the  bladder,  where  the  urethra  pas;>es 
off  from  it.  The  orifice  of  the  urethra  is  situated  ante- 
riorly at  the  lowermost  part  of  the  bladder.  On  the  low- 
er surface  of  the  urethra,  at  its  commencement,  and  on 
the  bottom  of  the  bladder,  immediately  connected  with 
the  urethra,  is  situated  the  Prostate  Gland.,  (to  be  here- 
after described  with  the  organs  of  generation,)  which  is  a 
firm  body,  that  adheres  strongly  both  to  the  hladder  and 
urethra.  This  circumstance  gives  particular  firmness  and 
solidity  to  that  part  of  the  bladder.  It  has  also  been  ob- 
served, that  the  bladder  is  attached  firmly  to  the  ossa 
pubis,  at  its  neck,  about  the  origin  of  the  urethra.  E>ch 
of  these  circumstances  have  an  effect  upon  the  orifice  of 
the  urethra;  and  when  the  bladder  is  opened,  and  this  ori- 
fice is  examined  from  within,  it  appears  to  be  kept  open 
by  the  connexion  of  the  bladder  with  the  prostate,  and 
has  been  very  justly  compared  to  the  opening  of  the  neck 
of  a bottle  into  the  great  cavity  of  that  vessel.* 

The  orifices  of  the  two  ureters  are  at  equal  distances 
from  the  orifice  of  the  urethra,  and  form  with  it  the  an- 
gles of  a triangle.  That  part  of  the  internal  surface  of 
the  bladder  which  is  within  this  triangular  space,  is  more 
smooth  than  the  remainder  of  the  same  surface,  probably 
in  consequence  of  the  adhesion  of  the  bladder  to  the 
prostate,  and  to  other  parts  exterior  to  it. 

That  part  of  the  bottom  of  the  bladder  which  is  imme- 
diately behind  the  triangular  space,  i§  rather  lower  than 

* The  late  Mr.  Lieutaud,  and  after  him  the  French  anatomists  of 
the  present  day,  have  described  a small  tubercle  at  the  lower  and 
posterior  part  of  the  orifice  of  the  urethra,  which  resembles  the  uvu- 
la in  form  It  has  not  been  noticed  here;  and  M.  Boyer  states,  that 
it  is  often  scarcely  preceptible.  He,  however,  makes  a remark  which 
is  very  worthy  of  attention,  viz.  that  it  is  very  subject  to  enlarge- 
ment in  old  people,  forming  a tumor  which  impedes  the  discharge 
of  urine.  Sabatier  has  also  made  the  same  observatiou. 


Ligaments  and  Vessels  of  the  Bladder • 1 65 

this  space;  and  but  a small  portion  of  cellular  membrane 
exists  between  it  and  the  rectum  in  males,  and  the  va- 
gina in  females. 

The  upper  part  of  the  bladder  is  connected  with  the 
umbilicus  by  means  of  a ligament,  which  passes  between 
the  peritoneum  and  the  abdominal  muscles.  This  liga- 
ment consists  of  three  cords.  One  of  these,  which  is. 
in  the  middle,  arises  from  the  coats  of  the  bladder,  and 
was,  in  the  foetus,  the  duct  called  urachus;  the  other 
two,  which  are  connected  to  the  bladder  principally  by 
cellular  membrane,  were  originally  the  umbilical  arte- 
ries.* The  middle  cord  is  of  a light  colour  and  fibrous 
structure;  it  is  thickest  at  the  bladder,  and  gradually  di- 
minishes as  it  approaches  the  umbilicus.  In  a few  in- 
stances it  has  Leen  found  to  be  hollow.  In  its  progress 
to  the  umbilicus  it  becomes  more  or  less  blended  with 
the  linea  alba,  or  the  tendons  of  the  abdominal  muscles. 
The  other  cords  are  generally  solid.  After  passing  from 
the  umbilicus  to  the  bladder,  they  continue  on  the  sides 
of  that  viscus,  and  finally  terminate  at  the  hypogastric  or 
internal  iliac  artery. 

In  the  very  young  subject  these  cords  are  invested  by 
distinct  processes  of  the  peritoneum,  but  their  position 
is  exterior  to  the  peritoneum. 

As  the  bladder  is  situated  very  near  most  of  the  large 
ramifications  of  the  hypogastric  artery  in  the  pdvis,  it 
receives  branches  from  several  of  them;  viz.  from  the 
umbilical  arteries  before  they  terminate;  from  the  pudic; 
from  the  obturators,  &.c.  These  branches  ramify  in  the 
cellular  membrane  exterior  to  the  muscular  coat,  and 
also  in  the  cellular  substance  between  the  muscular  and 
internal  coats.  It  has  been  conjectured , that  their  termi- 
nations in  exhalents  on  the  surface  of  the  bladder  are  re- 
markably numerous. 

* See  the  accounts  of  these  parts  in  the  description  of  the  Abdo- 
men of  the  Foetus. 


164 


General  Observations . 


The  veins  correspond  with  the  arteries,  but  they  are 
very  numerous  on  the  lower  and  lateral  parts  of  the  blad- 
der, and  by  uniting  with  the  veins  of  the  rectum  form  a 
remarkable  plexus. 

The  Lymphatic  Vessels  of  this  organ  do  not  appear 
more  numerous  than  those  of  other  parts.  They  pass  on 
each  side  the  bladder  in  the  course  of  its  bloodvessels, 
and  unite  with*  the  larger  lymphatics,  and  the  glands 
which  lie*  upon  the  great  bloodvessels  on  the  sides  of  the 
pelvis. 

The  Nerves  of  the  bladder  are  derived  both  from  the 
intercostal  nerve  and  from  the  nerves  of  the  medulla  spi- 
nalis, which  pass  off  through  the  sacrum;  and  therefore 
the  bladder  is  more  affected  than  the  viscera  of  the  abdo- 
men, by  injuries  of  the  medulla  spinalis. 

The  action  of  the  muscular  fibres  of  the  bladder  in  expelling 
urine,  and  the  effect  of  those  fibres  which  are  situated  near  the 
orifice  of  the  urethra  in  retaining  it,  can  be  considered  with 
more  advantage  after  the  structure  of  the  urethra  and  the 
muscles  connected  with  that  canal  have  been  described. 

It  has  been  stated,  that  the  internal  coat  of  the  bladder  is 
very  sensible;  but  it  may  be  added,  that  in  consequence  of  dis- 
ease about  the  neck  of  the  bladder,  the  natural  sensibility  ap- 
pears most  inordinately  increased.  When  the  intensity  of  pain 
which  accompanies  these  complaints,  the  frequent  recurrence 
of  paroxysms,  and  their  duration,  are  taken  into  view,  there 
seems  reason  to  believe  that  none  of  the  painful  affections  of 
the  human  race  exceed  those  which  arise  from  certain  dis- 
eases of  the  bladder.  Happily  these  diseases  are  not  very 
common. 

The  function  of  the  kidneys  is  to  secrete  urine,  and  that  of 
the  bladder  to  retain  it  until  the  proper  time  for  evacuation. 

The  urine  may  be  regarded  as  an  excrementitious  fluid, 
which  contains  many  substances  in  solution  that  are  constant- 
ly found  in  it,  and  many  others  that  are  occasionally  in  it, 
which  are  taken  as  aliment  or  medicine,  and  pass  to  the  blad- 
der with  little,  if  any,  change.  The  odour  of  the  rose  leaf,  the 
colour  of  rhubarb,  &c.  are  occasionally  perceived  in  urine. 

The  substances  constantly  found  in  urine  are  numerous. 


General  Observations , 


165 


The  chemical  account  of  the  subject  is  so  long,  that  it  cannot 
be  detailed  here;  but  the  student  ought  to  make  himself  ac- 
quainted with  it,  and  he  will  read  with  great  advantage  John- 
son’s History  of  Animal  Chemistry,  vol.  2d,  page  363;  and 
also  Thompson’s  Elements  of  Chemistry,  page  333. 


166 


CHAPTER  V. 

OF  THE  MALE  ORGANS  OF  GENERATION. 

THESE  organs  consist,  1st,  of  the  Testicles,  and  their 
appendages. 

2d.  Of  certain  parts  denominated  the  Vasicula  Semi- 
nales  and  the  Prostate  Gland,  which  are  situated  near 
the  commencement  of  the  urethra,  and  are  subservient  to 
the  purposes  of  generation. 

3d.  Of  the  Penis. 


SECTION  I. 

Of  the  Testicles  and  their  appendages. 

THE  Testicles  are  two  bodies  of  a flattened  oval  form. 
Each  of  them  has  a protuberance  on  its  upper  and  poste- 
rior part  called  Epididymis , and  is  connected  to  parts 
within  the  cavity  of  the  abdomen  by  a thick  cord,  which 
proceeds  to  it  through  the  abdominal  ring.  Each  testicle 
also  appears  to  be  contained  in  a sac,  which  is  suspended 
by  this  cord  and  covered  by  the  common  integuments. 

That  portion  of  the  common  integuments  which  forms 
the  external  covering  of  the  testicles,  is  denominated 

The  Scrotum. 

The  skin  of  the  scrotum,  although  it  is  very  often  in  a 
state  of  corrugation,  has  the  same  structure  with  that  on 
other  parts  of  the  body,  except  that  it  is  rather  thinner 


167 


Structure  of  the  Scrotum. 

and  more  delicate.  The  superior  delicacy  of  this  portion 
of  the  skin  is  evinced  by  the  great  irritation  produced  by 
the  application  of  stimulating  substances,  and  the  desqua- 
mation of  the  cuticle,  which  seems  to  be  the  effect  of  ir- 
ritation. There  are  many  sebaceous  follicles  in  this  portion 
of  skin;  and  after  puberty  there  are  often  a few  long  hairs 
growing  out  of  it,  the  bulbs  df  which  are  often  very  con- 
spicuous. There  is  a small  raised  line  in  the  middle  of 
this  skin,  which  commences  at  the  root  of  the  penis,  and 
proceeds  backwards,  dividing  it  into  two  equal  parts:  this 
line  is  denominated  Raphe. 

The  corrugation  which  so  often  takes  place  in  the  skin 
of  the  scrotum,  appears  to  be  occasioned  by  the  contrac- 
tion of  certain  fibres,  which  are  in  the  cellular  substance 
immediately  within  it.  This  cellular  substance  appears  to 
be  attached  in  a particular  way  to  the  skin;  and  it  also  in- 
vests each  testicle  in  such  a manner,  that  when  they  are 
Withdrawn  a cavity  is  left  in  it.  It  has  long  been  observed, 
that  no  adipose  matter  is  found  in  this  cellular  substance; 
but  it  is  often  distended  with  water  in  hydropic  diseases. 
As  the  contraction  and  corrugation  of  the  scrotum  has 
been  imputed  to  this  substance,  it  has  been  examined  with 
particular  attention  by  anatomists,  and  very  different  sen- 
timents have  been  entertained  respecting  it.  While  some 
dissectors  have  asserted  that  muscular  fibres  could  be 
seen  in  it,  which  they  have  denominated  the  Dartos  Mus- 
cle; others  hav^  said  that  this  substance  was  simply  cellu- 
lar, and  without  any  muscular  fibres.  This  difference  of 
sentiment  may  possibly  have  arisen  from  the  different 
conditions  of  this  part  in  different  subjects;  for  in  some 
cases  there  are  appearances  w’hich  seem  to  justify  the  as- 
sertion that  muscular  fibres  exist  in  this  structure. 

After  the  testicles  are  removed,  so  as  to  leave  the  cel- 
lular substance  connected  with  the  skin,  if  the  scrotum  be 
inverted,  and  this  substance  examined'  in  a strong  light, 
many  fibres  will  appear  superadded  to  the  common  cellu- 


168  Action  of  the  Dart  os  Muscle. 

lar  structure;  and  sometimes  their  colour  can  be  distin- 
guished to  be  red.  It  is  not  asserted  that  this  will  be 
uniformly  the  case;  but  certainly  it  has  often  been  ob- 
served in  this  way. 

The  existence  of  an  organ  which  possesses  the  power 
of  contraction,  within  the  skin  of  the  scrotum  and  con- 
nected to  it,  is  evinced  by  the  corrugation  which  takes 
place  when  the  scrotum  is  suddenly  exposed  to  cold, 
after  having  been  very  warm.  This  corrugation  occurs 
in  a very  sudden  and  rapid  manner,  in  some  cases,  in 
which  the  wounded  scrotum  is  thus  exposed  for  the 
purpose  of  dressing:  for  example,  upon  removing  an 
emollient  poultice  from  this  part  some  days  after  the 
operation  for  the  cure  of  hydrops  testis,  by  incision;  if 
the  air  of  the  chamber  be  cool,  a motion  of  the  scrotum 
will  take  place,  almost  equal  to  the  peristaltic  move- 
ments of  the  intestines. 

The  Arteries  of  the  scrotum  are  derived  from  two 
sources.  One  or  two  small  arteries,  which  arise  from  the 
femoral  artery,  between  Poupart’s  ligament  and  the  ori- 
gin of  the  profunda,  are  spent  upon  it.  These  are  called 
the  external  pudic  arteries.  It  also  receives  some  small 
branches  from  the  internal  pudic  artery. 

The  Nerves  of  the  scrotum  are  principally  derived 
from  the  lumbar  nerves. 


The  Spermatic  Cord. 

The  cord  which  proceeds  to  the  testicle  through  the 
abdominal  ring,  appears  at  first  view  like  a bundle  of 
muscular  fibres;  but  it  consists  of  an  artery  and  veins, 
with  many  lymphatic  vessels  and  nerves,  and  also  the 
excretory  duct  of  the  testicle,  connected  to  each  other 
by  cellular  substance,  and  covered  by  an  expansion  of 
muscular  fibres  which  are  derived  from  the  lower  edge 
of  the  interna]  oblique  muscle  of  the  abdomen,  and  con- 


Cremaster  Muscle.  Bloodvessels  of  the  Testicle.  169 

tinue  from  it  to  the  upper  part  of  the  testicle.  These 
fibres  constitute  the  Cremaster  Muscle . 

The  artery  above  mentioned  is  called  the  Spermatic. 
It  commonly  arises  from  the  front  of  the  aorta,  very 
near  its  fellow,  at  a small  distance  below  the  emulgents: 
and  is  not  much  larger  than  a crow’s  quill.  It  proceeds 
downwards  behind  the  peritoneum  and  before  the  psoas 
muscle  and  ureter.  While  it  is  in  contact  with  the  psoas 
muscle,  it  joins  the  ramifications  of  the  vein.  It  after- 
wards meets  the  vas  deferens,  and  proceeds  through  the 
abdominal  ring  to  the  back  part  of  the  testis.  Before  it 
arrives  at  the  testis  it  divides  into  several  branches,  two 
of  which  generally  go  to  the  epididymis,  and  the  others 
penetrate  the  tunica  albuginea  on  the  upper  and  back  of 
the  testicle,  and  ramify  very  minutely  on  the  fine  membra- 
nous partitions  which  exist  in  that  body. 

In  addition  to  the  spermatic  artery,  there  is  a small 
twig  from  the  umbilical  branch  of  the  hypogastric,  which 
passes  to  the  spermatic  cord  along  the  vas  deferens. 

The  branches  of  the  spermatic  vein  are  much  larger 
than  those  of  the  artery:  several  of  them  proceed  from 
the  testicle  so  as  to  correspond  with  the  arterial  branches; 
and  in  addition  to  these  there  are  many  smaller,  which 
also  arise  from  the  testicle  and  epididymis.  In  their 
course  up  the  cord  they  ramify,  and  again  unite,  so  as  to 
form  a considerable  plexus,  which  is  called  the  Corpus 
Pampiniforme , and  constitutes  a considerable  part  of  the 
volume  of  the  spermatic  cord. 

As  they  proceed  upwards  they  unite  into  a few  larger 
veins;  and  finally,  on  the  psoas  muscle,  they  generally 
form  one  trunk,  which  continues  upwards  so  as  to  unite 
with  the  vena  cava  on  the  right  side  and  the  emulgent 
vein  on  the  left. 

Sometimes,  but  not  often,  there  are  several  spermatic 
veins  on  each  side. 

The  Lymphatic  Vessels  of  the  testicle  are  very  numer- 
Vol.  II.  Y 


170  Lymphatics  and  Nerves  of  the  Spermatic  Cord. 

ous,  considering  the  size  of  the  organ.  Six  or  eight,  and 
sometimes  more,  large  trunks  have  been  injected,  run- 
ning upon  the  cord,  and  continuing  to  the  glands  on  the 
back  part  of  the  abdomen. 

The  Nerves  of  the  testicle  are  derived  from  those 
which  supply  the  viscera  of  the  abdomen,  and  are  to  be 
found  in  the  cord  although  they  can  scarcely  be  traced 
to  the  testicle.  A small  plexus,  called  the  spermatic,  is 
formed  by  fibres  from  the  renal  plexus  and  from  the 
sympathetic  nerve.  These  fibres  accompany  the  sper- 
matic vessels,  and  in  all  probability  enter  the  body  of 
the  testis  and  the  epididymis.  The  spermatic  cord  and 
cremaster  muscle  receive  filaments  from  the  second 
lumbar  nerve. 

In  addition  to  these  vessels,  the  Fas  Deferens,  which 
is  much  firmer  than  either  of  them,  is  always  to  be  dis- 
guished  in  the  back  part  of  the  cord. 

They  are  all  covered  in  front  and  on  the  sides  by  the 
cremaster  muscle,  which  passes  with  them  from  the 
lower  margin  of  the  internal  oblique,  through  the  abdo- 
minal ring,  and  continues  to  the  upper  part  of  the  ex- 
ternal coat  of  the  testicle,  which  is  a sac  apparently  con- 
taining that  organ,  and  upon  this  sac  it  is  spread  out  and 
terminates. 


The  Tunica  Vaginalis. 

The  External  Coat  of  the  testicle,  which  is  commonly 
called  the  Tunica  Vaginalis,  is  a complete  sac  which  in- 
closes the  testicle  as  the  pericardium  incloses  the  heart. 
It  covers  the  body  of  the  testicle  and  epididymis,  and 
adheres  closely  to  them.  It  is  then  reflected  from  them 
so  as  to  form  a loose  sac,  which  appears  to  contain  them. 
The  cavity  of  the  tunica  vaginalis  commonly  extends 
above  the  body  of  the  testis  up  the  cord,  and  is  oval  or 
pyriform.  This  sac  is  so  reflected  from  the  body  of  the 


271 


Coats  of  the  Testicle . 

testicle,  that  there  is  a place  on  the  upper  and  back 
part  of  that  body  at  which  the  bloodvessels  enter  it, 
without  penetrating  the  sac. 

It  resembles  the  peritoneum  and  other  serous  mem- 
branes in  texture,  and  is  therefore  thin  and  delicate.  It 
always  contains  a quantity  of  moisture,  sufficient  to  lu- 
bricate the  surface  which  it  forms. 

When  the  tunica  vaginalis  is  laid  open,  the  testicle  ap- 
pears as  if  it  were  contained  in  the  posterior  part  of  its 
cavity. 

The  testicles,  as  has  been  already  stated,  are  of  a flat- 
tened oval  form.  Their  position  is  somewhat  oblique,  so 
that  their  upper  extremities  look  upwards  and  forwards, 
their  lower  extremities  downwards  and  backwards,  and 
their  edges  present  forwards  and  backwards. 

The  body  of  the  testicle  is  very  firm,  in  consequence 
of  its  inclosure  in  a very  firm  coat  called  Tunica  Albugi- 
nea. Upon  the  upper  and  posterior  part  of  it  is  the  pro- 
tuberant substance,  called  Epididymis , which  is  less  firm, 
being  exterior  to  the  tunica  albuginea.  The  bloodvessels 
of  the  testicle  pass  into  it  on  the  posterior  edge,  at  some 
distance  below  the  upper  end. 

The  Tunica  Albuginea , 

In  which  the  body  of  the  testicle  is  completely  inclos- 
ed, is  firm  and  dense;  and  upon  this  coat  its  particular 
form  depends.  It  is  of  a whitish  colour,  and  has  a smooth 
external  surface.  It  is  thick  as  well  as  strong,  The  epi- 
didymis is  exterior  to  it.  It  is  only  perforated  by  the 
bloodvessels,  lymphatics  and  nerves,  and  by  the  vasa 
efferentia,  which  carry  out  the  secretion  of  the  testis. 
One  portion  of  the  tunica  vaginalis  adheres  very  closely 
to  it,  and  the  other  appears  to  contain  it.  The  portion 
which  adheres  to  it  is  with  difficulty  separated,  but  it  is 
a distinct  membrane. 


172  Form  and  Connect  mis  of  the  Epididymis . 

The  Epididymis 

Differs  in  colour  from  the  testicle,  being  more  or  less 
reddish.  It  commences  at  the  upper  and  anterior  extre- 
mity of  the  testicle,  and  passes  down  the  posterior  edge 
to  the  lower  end. 

At  the  commencement  the  epididymis  is  somewhat 
rounded  in  form,  and  its  upper  part,  or  head,  has  been 
called  the  globus  major:  as  it  descends  it  lessens,  and 
about  the  middle  of  the  testicle  it  is  flattish. 

It  is  firmly  attached  to  the  body  of  the  testicle,  at  the 
upper  end,  where  the  vasa  efferentia  pass  to  it;  and  it  is 
also  attached  to  it  below;  but  at  the  middle  it  appears 
nearly  detached  from  it.  It  has  therefore  been  compared 
to  an  arch  resting' with  its  two  extremities  on  the  back  of 
the  testis;  iti^,  however,  in  contact  with  it  at  its  middle; 
but  about  the  middle  it  only  adheres  by  one  of  its  edges 
to  the  body  of  the  testis,  and  generally  by  its  internal 
edge.  It  has  a coat  which  is  less  firm  than  the  tunica 
albuginea  of  the  testicle,  described  on  the  last  page.  The 
tunica  vaginalis  of  the  testicle  is  so  reflected  as  to  cover  a 
great  part  of  the  epididymis  which  is  not  in  contact  with 
the  testicle,  and  also  those  surfaces  of  the  epididymis  and 
testis  which  are  in  contact  with  each  other  and  do  not  ad- 
here. 

The  Body  of  the  Testicle. 

When  the  tunica  albuginea  is  cut  through,  and  the 
substance  of  the  testicle  examined,  it  appears  to  consist 
of  a soft  pulpy  substance  of  a yellowish  brown  colour, 
which  is  divided  into  separate  portions  by  very  delicate 
septa,  attached  to  the  internal  surface  of  the  tunica  albu- 
ginea at  the  posterior  part  of  the  testicle.  After  macera- 
tion, by  using  a fine  needle  to  detach  them  from  the  cel- 
lular substance,  these  threads  may  be  drawn  out  to  a 
great  length.  In  some  animals  they  are  larger  than  in  the 


Tubuli,  Septa  and  Bloodvessels  of  the  Testicle . 173 

human  species;  in  them,  it  is  said,  they  are  evidently  hol- 
low, and  that  very  small  bloodvessels  appear  in  their  coats. 
When  mercury  is  injected  into  the  vas  deferens,  or  excre- 
tory duct  of  the  testis,  in  a retrograde  course,  it  can  be 
perceived  in  these  ducts  in  the  human  subject. 

These  delicate  septa,  or  partitions,  are  united  to  the  in- 
ternal surface  of  the  tunica  albuginea  at  the  posterior  part 
of  the  testicle,  at  which  place  there  is  a body  called 
Corpus  Highmorianum , which  has  been  regarded  very  dif- 
ferently by  different  anatomists.  It  is  a long  whitish  sub- 
stance, which  extends  lengthwise  on  the  posterior  part 
of  the  testis;  and  was  supposed  by  Haller  to  resemble 
one  of  the  salivary  ducts.  It  is  now,  however,  generally 
agreed  to  be  of  a cellular  structure,  and  to  contain  and 
support  the  ducts  which  pass  from  the  substance  of  the 
testicle  to  the  epididymis. 

The  bloodvessels  pass  into  the  body  of  the  testicle 
upon  these  septa,  and  are  continued  from  them  to  the  fila- 
ments or  tubes  of  which  the  body  of  the  testicle  consists. 
As  in  some  animals  bloodvessels  are  distinguished  on 
these  tubes,  there  is  the  greatest  reason  to  believe  that  a 
direct  communication  subsists  between  them,  without  the 
intervention  of  any  other  structure,  no  other  structure  hav- 
ing been  discovered;  but  at  the  same  time  it  ought  to  be 
observed,  that  these  tubes  have  not  yet  been  injected 
from  the  bloodvessels.  Some  ingenious  anatomists  have 
injected  the  artery  going  to  the  testicle  so  successfully, 
that  the  injection  has  passed  from  it  into  the  veins  coming 
out  of  the  testicle;  but  it  is  not  now  said  by  any  of  them, 
that  they  have  filled  the  tubes  in  this  manner. 

Mercury  will  pass  into  these  vessels  from  the  excre- 
tory duct  of  the  testicle;  and  by  means  of  an  injection  in 
that  way,  the  structure  of  the  testicle  can  be  unravelled. 

This  structure  is  as  follows:  The  cavity  formed  by  the 
tunica  albuginea  is  divided  into  a number  of  apartments  by 
the  very  thin  septa,  or  partitions,  above  mentioned.  From 


174  Structure  of  the  Testicle  and  Epididymis . 

the  filamentary  or  tubular  matter  which  fills  each  of  these 
chambers,  proceeds  a number  of  small  tubes  or  vessels, 
which  observe  a straight  course;  they  are  therefore  called 
Vasa  Recta.  These  vasa  recta  unite  with  each  other  and 
form  a network  on  the  back  of  the  testis,  within  the  tu- 
nica albuginea,  which  is  called  Rete  Testis.  From  this 
network  other  vessels,  from  twelve  to  eighteen  in  number, 
denominated  Vasa  Ejferentia , proceed  through  the  albugi- 
nea to  the  epididymis.  These  vessels  are  convoluted  in 
such  a manner  as  to  form  bundles  of  a conical  form,  which 
are  called  Coni  Vasculosi.  The  number  of  these  corres- 
ponds with  the  number  of  the  vasa  efferentia,  and  they 
compose  about  one  third  of  the  epididymis,  viz.  all  the 
upper  part  of  it.  The  single  tubes  which  form  each  of 
these  cones,  successively  unite  into  one  duct,  which  is 
convoluted  so  as  to  form  all  the  remainder  of  the  epidi- 
dymis. The  lower  part  of  the  epididymis  is  turned  up- 
wards on  the  back  of  the  testicle,  the  tube  gradually  en- 
larges  and  is  less  convoluted,  and  finally  becomes  straight: 
it  then  takes  the  name  of  V is  Deferens , and  continues  on 
the  back  of  the  testicle  to  the  spermatic  cord.* 

A small  solitary  vessel  or  duct,  has  been  observed  by 
Haller,  Monro,  and  several  other  anatomists,  to  proceed 
from  the  upper  part  of  the  epididymis:  sometimes  it 

* De  Graff  appears  to  have  been  the  first  anatomist  who  made 
much  progress  in  the  successful  investigation  of  the  structure  of  the 
testicle;  and  Haller  ought  to  be  mentioned  next  to  him,  on  account 
of  the  plate  exhibiting  this  structure,  and  the  explanation  of  it,  which 
he  published  in  the  Philosophical  Transactions  of  London,  for  1749. 
This  plate  has  been  republished  by  the  second  Monro,  in  the  Lite- 
rary and  Physical  Essays  of  Edinburgh,  and  also  in  his  Inaugural 
Thesis.  Haller  has  likewise  republished  it  in  his  Opera  Minora-  It 
represents  not  only  the  vasa  efferentia  and  the  cones  formed  by 
their  convolutions,  but  also  the  rete  testis  and  the  vasa  recta.  Haller 
could  inject  no  further  than  this;  but  Monro  and  Hunter  soon  after 
succeeded  so  as  to  fill  a considerable  portion  of  the  body  of  the  tes- 
ticle with  mercury,  injected  by  the  vas  deferens. 


175 


Course  of  the  Vas  Deferens . 

unites  to  the  epididymis  below,  and  sometimes  it  pro- 
ceeds upwards.  The  nature  of  this  vessel  has  not  been 
ascertained  with  certainty. 

The  Fas  Deferens 

Is  a very  firm  tube  about  two  lines  in  diameter,  which 
is  not  perfectly  cylindrical  exteriorly,  although  the  cavity 
formed  by  it  is  so.  This  cavity  is  so  small  in  diameter, 
that  it  will  only  admit  a fine  bristle.  The  coats  of  the 
duct  have,  of  course,  a considerable  thickness.  The  in- 
ternal coat  forms  a soft  surface,  analogous  to  that  of  the 
mucous  membranes:  the  external  is  firm,  and  its  texture 
resembles  that  of  cartilage.  Owing  to  the  small  size  of 
the  cavity,  the  internal  coat  has  not  been  separated  from 
the  external. 

It  passes  upwards  in  the  posterior  part  of  the  spermatic 
cord,  and  continues  with  it  through  the  abdominal  ring, 
under  and  exterior  to  the  peritoneum;  soon  after  this  it 
leaves  the  cord  and  dips  down  into  the  cavity  of  the  pel- 
vis, forming  a curve  on  the  side  of  the  bladder,  and  pro- 
ceeding backwards,  downwards  and  inwards.  In  this 
course  it  crosses  the  ureter,  and  passes  between  it  and  the 
bladder.  On  the  lower  part  of  the  bladder  the  two  vasa 
deferentia  approach  each  other  so  gradually,  that  they  ap- 
pear to  be  nearly  parallel.  They  proceed  forward  be- 
tween the  vesiculse  seminales,  which  are  two  bodies  irre- 
gularly convoluted,  that  are  placed  in  a converging  posi- 
tion with  respect  to  each  other,  and  communicate  with 
the  vasa  deferentia.  The  vasa  deferentia  finally  terminate 
almost  in  contact  with  each  other  in  the  posterior  part  of 
the  prostate  gland,  where  they  perforate  the  urethra.  At 
the  distance  of  about  two  inches  and  a half  from  their 
termination  they  enlarge  in  diameter,  and  become  some- 
what convoluted.  At  the  posterior  margin  of  the  prostate 
they  come  in  contact  with  the  anterior  extremities  of  the 


176  Structure  of  the  Vesicula  Seminales. 

vesiculse  seminales,  and  unite  with  them.  After  this  union 
they  diminish  in  size,  and  become  conical;  and  passing* 
a short  distance  through  the  substance  of  the  prostate, 
during  which  they  approach  each  other  more  rapidly, 
they  penetrate  the  urethra,  so  as  to  open  in  it  on  each 
side  o 1 a small  tubercle,  called  the  Caput  Gallinaginisy 
soon  to  be  described. 


SECTION  II. 

Of  the  V esicula  Seminales  and  the  Prostate  Gland . 

THE  Vesicula  Seminales  are  two  bodies  of  a whitish 
colour,  and  irregular  form,  being  broad  and  flat  at  their 
posterior  extremities,  and  terminating  in  a point  at  the 
other.  Their  surfaces  are  so  convoluted,  that  they  have 
been  compared  to  those  of  the  brain.  They  are  situated 
between  the  rectum  and  bladder,  and  are  connected  to 
each  by  cellular  membrane. 

When  the  vesiculae  seminales  are  laid  open  by  an  in- 
cision, they  appear  to  consist  of  cells  of  a considerable 
size,  irregularly  arranged;  but  when  they  are  carefully 
examined  exteriorly,  and  the  cellular  membrane  about 
them  is  detached  and  divided,  they  appear  to  be  formed 
by  a tube  of  rather  more  than  two  lines  diameter,  and  se- 
veral inches  in  length,  which  terminates,  like  the  cascum, 
in  a closed  extremity.  From  this  tube  proceed  from  ten  to 
fifteen  short  branches,  which  are  closed  in  the  same  man- 
ner. All  these  tubes  are  convoluted  so  as  to  assume  the 
form  of  the  vesicula:  seminales  above  described;  and  they 
are  fixed  in  this  convoluted  state  by  cellular  membrane, 
which  firmly  connects  their  different  parts  to  each  other. 
It  is  obvious,  that  tubes  thus  convoluted,  when  cut  into, 
will  exhibit  the  appearance  of  cells,  as  in  the  present  in- 
stance. 


Function  of  the  Vesiculce  Seminales.  177 

This  convoluted  tube,  composing  the  vesiculae  semi- 
nales, terminates  in  a very  short  duct,  which  is  nearly  of 
the  same  diameter  with  the  vas  deferens,  and  this  duct 
joins  the  vas  deferens  so  as  to  form  an  acute  angle. 

From  the  union  of  the  vesiculae  seminales  with  the  vas 
deferens  on  each  side,  a canal,  which  seems  to  be  the 
continuation  of  the  vas  deferens,  proceeds  through  part  of 
the  prostate  to  the  urethra,  which  it  perforates.  These 
canals  are  from  eight  to  twelve  lines  in  length;  they  are 
conical  in  form,  their  largest  extremity  being  equal  to 
the  vas  deferens  at  that  part. 

If  air  or  any  other  fluid  be  injected  through  the  vas  de- 
ferens into  the  urethra,  it  will  pass  at  the  same  time  into 
the  vesiculce  seminales,  and  distend  them.  It  has  been  ob- 
served, that  a fluid  passes  in  this  manner  much  more 
readily  from  the  vasa  deferentia  into  the  vesiculae  semi- 
nales, than  it  does  from  these  last  mentioned  organs  into 
the  duct. 

These  organs  were  generally  regarded  as  reservoirs  of 
semen,  and  analogous  to  the  gall  bladder  in  their  func- 
tions, until  the  late  Mr.  J.  Hunter  published  his  opinion 
that  they  were  not  intended  to  contain  semen,  but  to  se- 
crete a peculiar  mucus  subservient  to  the  purposes  of  ge- 
neration. 

He  states  the  following  facts  in  support  of  his  opinion. 

A fluid,  very  different  from  semen,  is  found  after  death 
in  the  vesiculae  seminales. 

In  persons  who  have  lost  one  testicle,  a considerable 
time  before  death,  the  vesiculae  seminales  on  each  side 
are  equally  distended  with  this  peculiar  fluid. 

The  sensation  arising  from  redundance  of  the  secretion 
of  the  testes,  is  referred  to  the  testes,  and  not  to  the  vesi- 
culae seminales. 

In  some  animals,  there  is  no  connection  between  the 
vasa  deferentia  and  the  vesiculae  seminales. 

Vol.  II.  Z 


178 


Prostate  Gland. 


See  Observations  on  certain  parts  of  the  Animal  Eco- 
nomy, by  John  Hunter. 

The  Prostate  Gland 

Is  situated  on  the  under  and  posterior  part  of  the  neck 
of  the  bladder,  so  as  to  surround  the  lower  side  of  the 
urethra.  Its  form  has  some  resemblance  to  that  of  the 
chesnut,  but  it  has  a notch  on  the  basis  like  that  of  the 
figure  of  the  heart  on  playing  cards,  and  it  is  much  larger 
than  the  chesnut  of  this  part  of  America.  The  basis  of  this 
body  is  posterior,  and  its  apex  anterior;  its  position  is 
oblique,  between  the  rectum  and  the  symphisis  pubis.  On 
the  upper  surface  is  the  groove  occupied  by  the  urethra; 
below  there  is  in  some  cases  a small  furrow,  which,  in 
addition  to  the  notch  above,  gives  to  the  gland  an  appear- 
ance of  being  divided  into  two  lobes. 

It  adheres  to  the  urethra  and  neck  of  the  bladder.  Its 
consistence  is  very  firm  and  dense,  resembling  the  indu- 
ration of  scirrhus  rather  more  than  the  ordinary  texture 
of  glands. 

This  gland  receives  small  branches  from  the  neighbour- 
ing bloodvessels,  and  has  no  artery  of  considerable  size 
exclusively  appropriated  to  it. 

As  it  lies  in  close  contact  with  the  urethra,  the  ducts 
which  pass  between  it  and  the  urethra  are  not  to  be  seen 
separate  from  these  bodies;  but  ducts  can  be  seen  in  the 
substance  of  the  gland,  which  perforate  the  urethra,  and 
open  on  the  sides  of  the  caput  gallinaginis  to  the  number 
of  five  or  six  on  each  side.  By  pressure  a small  quantity 
of  a whitish  fluid  can  be  forced  from  these  orifices,  which 
is  rather  viscid,  and  coagulable  in  alcohol. 

The  particular  use  of  this  fluid  is  not  knowji. 


Penis. 


179 


SECTION  III. 

Of  the  Penis. 

THE  penis,  when  detached  from  the  bladder,  and  the 
bones,  to  which  it  is  connected,  and  divested  of  the  skin 
which  covers  it,  is  an  oblong  body,  which  is  rounded  at 
one  extremity  and  bifurcated  at  the  other. 

It  is  composed  of  three  parts,  viz.  two  oblong  bodies, 
called  Corpora  Cavernosa,  which,  at  their  commence- 
ment, form  the  bifurcated  portions,  and  then  unite  to  com- 
pose the  body  of  the  organ;  and  a third  part,  of  a spongy 
texture,  which  is  connected  to  these  bodies  where  they 
unite  to  each  other,  on  the  under  side,  and  continues  at- 
tached to  them  during  the  whole  extent  of  their  union, 
terminating  in  an  expanded  head  which  covers  the  ante- 
rior extremities  of  the  corpora  cavernosa.  The  urethra 
passes  from  the  neck  of  the  bladder,  on  the  under  side  of 
the  penis,  to  its  anterior  extremity,  invested  by  this  third 
body,  which  is  therefore  called  Corpus  Spongiosum  Ure- 
thra. 

The  two  bifurcated  extremities  are  attached  each  of 
them  to  one  of  the  crura  of  the  pubis  and  ischium;  and 
they  unite  to  form  the  body  of  the  penis  immediately  an- 
terior to  the  symphisis  pubis,  to  which  the  lower  part  of  it 
is  also  attached;  so  that  the  penis  is  firmly  connected  to  the 
middle  of  the  anterior  part  of  the  pelvis.  The  urethra 
proceeds  from  the  neck  of  the  bladder,  between  the  crura 
of  the  ischium  and  pubis  and  the  crura  of  the  penis,  to 
join  the  body  of  the  penis  at  its  commencement,  and  near 
this  place  its  connection  with  the  corpus  spongiosum  be- 
gins; so  that  there  is  a small  portion  of  the  urethra  between 
the  neck  of  the  bladder  and  the  commencement  of  the 
corpus  spongiosum,  which  is  not  covered  by  the  corpus 


ISO  Corpora  Cavernosa  Penis. 

spongiosum.  This  is  called  the  membranous  part  of  the 
urethra. 

The  penis,  therefore,  consists  of  two  oblong  bodies  of 
a cellular  structure,  which  originate  separately,  but  unite 
together  to  form  it;  and  of  the  urethra,  which  joins  these 
bodies  immediately  after  their  union,  and  is  invested  by  a 
spongy  covering,  which  by  its  expansion  forms  the  ante- 
rior extremity  not  only  of  the  urethra  but  of  the  whole 
penis.  These  three  bodies,  thus  arranged  and  connected, 
are  covered  by  cellular  membrane  and  skin  in  a manner 
to  be  hereafter  described. 

The  Corpora  Cavernosa , 

Which  compose  the  body  of  the  penis,  are  two  irre- 
gular cylinders,  that  are  formed  by  a thick  dense  elastic 
membrane,  of  a whitish  ligamentous  appearance  and 
great  firmness.  They  are  filled  with  a substance  of  a 
cellular  structure,  which  is  occasionally  distended  with 
blood.  The  crura  of  these  cylindrical  bodies,  which  are 
attached  to  the  crura  of  the  ischium  and  pubis,  are  small 
and  pointed  at  the  commencement,  and  are  united  to 
the  periosteum  of  the  bones.  In  their  progress  upwards 
they  enlarge,  and  at  the  symphisis  of  the  pubis  they 
unite  so  as  to  form  one  oblong  body,  which  retains  the 
appearance  of  a union  of  two  cylinders  applied  to  each 
other  lengthways;  for  above  there  is  a superficial  groove 
passing  in  that  direction,  which  is  occupied  by  a large 
vein;  and  below  there  is  a much  deeper  groove,  in  which 
the  urethra  is  placed.  Between  these  grooves  is  a septum 
which  divides  one  side  of  the  penis  from  the  other.  It 
appears  to  proceed  from  the  strong  membrane  which 
forms  the  penis,  and  is  composed  of  bundles  of  fibres, 
which  pass  from  one  groove  of  the  penis  to  the  other, 
with  many  intervals  between  them,  through  which  blood 
or  injection  passes  very  freely.  Sometimes  these  bundles 


181 


Cells  of  the  Corpora  Cavernosa . 

of  fibres,  with  their  intervals,  are  so  regularly  arranged, 
that  they  have  been  compared  to  the  teeth  of  a comb. 
This  septum  extends  from  the  union  of  the  two  crura  to 
their  termination. 

Each  of  these  cylinders  is  penetrated  by  the  main 
branch  of  the  pudic  artery,  which  is  about  equal  in  size 
to  a crow’s  quill.  These  arteries  enter  the  corpora  caver- 
nosa near  their  union,  and  continue  through  their  whole 
extent,  sending  off  branches  in  their  course:  the  turges- 
cence  and  erection  of  the  penis  is  unquestionably  pro- 
duced by  the  blood  which  flows  through  these  vessels  into 
the  penis. 

The  interior  structure  of  the  penis,  when  examined  in 
the  recent  subject,  is  of  a soft  spongy  nature,  and  seems 
stained  with  blood.  If  any  fluid  be  injected  through  the 
arteries  this  substance  appears  cellular,  and  may  be  com- 
pletely distended  by  it.  When  air  is  injected,  and  the 
structure  becomes  dry,  the  penis  may  be  laid  open;  the 
cellular  structure  then  appears  as  if  formed  by  a number 
of  laminae  and  of  filaments,  which  proceed  from  one  part 
of  the  internal  surface  of  the  penis  to  another,  and  form 
irregular  cells.  It  has  been  compared  to  the  lattice-work  in 
the  interior  of  bones;  and  it  is  suggested  by  M.  Roux, 
that  the  fibres  of  which  the  structure  consists  resemble 
those  of  the  strong  elastic  coat  of  the  penis.*  If  these  cells 
are  filled  with  coloured  wax,  injected  by  the  artery,  and 
the  animal  substance  is  then  destroyed  by  placing  the 
preparation  in  a corroding  liquor,  the  wax  which  remain^ 
shows  that  the  membranes  forming  the  cells  are  very 
thin. 

These  cells  communicate  freely  with  each  other;  and 
therefore,  if  a pipe  be  passed  through  the  strong  coat  of 
the  penis,  the  whole  of  them  can  be  filled  from  it  by  the 
ordinary  process  of  injection. 

* The  late  J.  Hunter  thought  they  were  muscular. 


182 


Corpus  Spongiosum.  Bulb . 


The  Urethra 

Is  a membranous  canal,  which  extends  from  the  neck 
of  the  bladder  to  the  orifice  at  the  extremity  of  the  penis; 
and  for  a very  great  part  of  its  length  is  invested  by  a 
spongy  structure,  called  the  corpus  spongiosum  urethrae. 
It  proceeds  from  the  neck  of  the  bladder  along  a groove 
in  the  upper  part  of  the  prostate;  from  the  prostate  it  con- 
tinues between  the  crura  of  the  penis  until  their  junction: 
it  then  occupies  the  great  groove  formed  by  the  corpora 
cavernosa  on  the  lower  side  of  the  penis,  and  continues 
to  the  orifice  above  mentioned.  At  a small  distance  from 
the  prostate  gland  the  spongy  substance  which  invests  it 
commences,  and  continues  to  its  termination.  After  this 
spongy  substance  has  arrived  at  the  termination  of  the 
corpora  cavernosa,  it  expands  and  forms  a body  of  a par- 
ticular figure  which  covers  the  extremities  of  the  corpora 
cavernosa,  and  is  denominated  the  Gians  Penis. 

The  Corpus  Spongiosum  begins  at  the  distance  of  eight 
or  ten  lines  from  the  anterior  part  of  the  prostate.  It  is 
much  larger  at  its  commencement  than  at  any  other  part 
except  the  glans,  and  this  enlarged  part  is  called  the  Bulb. 
It  surrounds' the  whole  of  the  urethra,  and  with  the  ex- 
ception of  the  bulb  and  the  glans  penis,  is  of  a cylindrical 
figure.  It  is  formed  by  a membrane  which  has  some  re- 
semblance to  the  coat  of  the  penis,  but  is  much  thinner, 
and  by  a peculiar  spongy  substance,  which  occupies  the 
space  between  the  internal  surface  of  this  membrane  and 
the  external  surface  of  the  canal  of  the  urethra.  The 
membrane  and  the  spongy  substance,  form  a coat  to  the 
urethra,- which,  with  the  exception  of  the  enlargement  be- 
fore mentioned,  is  about  two  lines  thick.  It  is  situated  in 
the  groove  on  the  lower  side  of  the  penis,  and  its  coat 
adheres  firmly  to  the  coat  of  the  penis. 

The  Bulb , or  first  enlargement  of  the  corpus  spongio- 
sum, is  oblong,  and  rather  oval  inform;  it  is  marked  by  a 


183 


Structure  of  the  Corpus  Spongiosum. 

longitudinal  depression  in  the  middle,  which  is  very  su- 
perficial. It  consists  entirely  of  the  spongy  substance  above 
mentioned. 

The  Gians  Penis  is  also  composed  of  the  same  spongy 
substance,  but  the  coat  which  covers  it  is  more  thin  and 
delicate  than  that  of  the  other  parts  of  the  urethra.  The 
lower  surface  of  the  glans  is  fitted  to  the  extremities  of 
the  corpora  cavernosa,  but  it  is  broader  than  the  corpora 
cavernosa,  and  therefore  projects  over  them  on  the  upper 
and  lateral  parts  of  the  surface  of  the  penis.  The  edge  of 
the  prominent  part  is  regularly  rounded,  and  is  denomi- 
nated the  Corona  Glandis. 

Several  small  arteries  pass  to  this  spongy  structure.  The 
pudic  artery,  as  it  passes  on  each  side  to  the  corpora  ca- 
vernosa, sends  a branch  to  the  bulb  of  the  urethra.  The 
same  vessel  in  the  substance  of  the  penis,  also  sends 
branches  to  the  urethra:  and  the  artery  on  the  back  of  the 
penis  terminates  in  small  branches,  which  penetrate  the 
substance  of  the  glans. 

By  these  vessels  blood  is  carried  to  the  spongy  sub- 
stance of  the  urethra,  which  is  occasionally  distended  in 
the  same  manner  that  the  cavernous  bodies  of  the  penis 
are  distended  during  the  erection  of  that  organ.  But  the 
cellular  structure  of  this  organ  is  not  so  unequivocal  as 
that  of  the  penis;  for  if  it  be  injected  with  coloured  wax, 
and  corroded  in  the  usual  manner,  the  injected  matter 
will  exhibit  an  appearance  which  has  the  strongest  resem- 
blance to  a convoluted  vessel,  like  the  vas  deferens  in  the 
epididymis. 

The  Canal  of  the  Urethra , 

Which  conveys  the  urine  from  the  bladder,  is  a very 
important  part  of  the  urinary  organs.  It  consists  of  a vas- 
cular membrane  with  a smooth  surface,  which  is  perfo- 
rated by  the  orifices  of  many  mucous  follicles,  some  of 


184  Internal  Surface  of  the  Urethra . 

which  are  of  considerable  size.  It  is  extremely  sensible, 
and  has  so  much  power  of  contraction,  that  some  persons 
have  supposed  muscular  fibres  to  exist  in  its  structure. 

It  is  differently  circumstanced  in  different  parts  of  its 
course.  While  surrounded  with  the  prostate  it  adheres 
firmly  to  that  body,  seeming  to  be  supported  by  it;  and 
here  its  diameter  is  larger  than  it  is  farther  forward.  On 
the  lower  or  posterior  side  of  this  portion  of  the  urethra, 
is  an  oblong  eminence,  called  Verwnontanum , or  Caput 
Gallinaginis,  which  commences  at  the  orifice  of  the  ure- 
thra, and  continues  throughout  the  whole  portion  that 
is  surrounded  by  the  prostate  gland,  terminating  at  the 
point  of  that  body.  The  posterior  extremity  of  this  tu- 
bercle begins  abruptly,  and  soons  becomes  thick  and 
large;  anteriorly  it  gradually  diminishes  to  a line,  which 
is  sometimes  preceptible  for  a considerable  distance  in 
the  urethra,  in  a straight  forward  direction.  In  the 
upper  edge  or  top  of  this  body  is  a groove,  which  is  pro- 
duced by  a mucous  follicle;  on  thp  lateral  surfaces,  ante- 
rior to  the  middle,  are  the  orifices  of  the  common  ducts 
of  the  vesiculae  seminales  and  vasa  deferentia  (see  page 
176,  7,)  which  are  sufficiently  large  to  receive  a thick 
bristle.  Near  these,  on  each  side,  are  five  or  six  smaller 
orifices  of  the  excretory  ducts  of  the  prostate  gland.  At 
a small  distance  before  the  caput  gallinaginis  are  the  open- 
ings of  two  ducts,  one  on  each  side,  that  lead  to  small 
glandular  bodies  called  Cowper's  glands,  which  are  situa- 
ted on  each  side  of  the  urethra  below  the  bulb,  but  are 
covered  by  the  accelerator  urinae  muscle. 

The  diameter  of  the  urethra  lessens  after  it  leaves  the 
prostate.  That  portion  of  the  canal  which  is  between 
this  gland  and  the  bulb,  without  investment,  and  there- 
fore called  the  membranous  part,  is  the  smallest  in  dia- 
meter. 

After  it  is  invested  with  the  spongy  substance  it  has  a 
small  enlargement,  and  then  continues  nearly  of  one 


185 


Mucous  Ducts  of  the  Urethra. 

size  until  it  arrives  near  the  glans  penis,  when  it  again 
enlarges  and  alters  its  form,  being  no  longer  cylindrical 
but  flattened.  Its  broad  surfaces  have  now  a lateral  aspect. 

From  the  bulb  of  the  corpus  spongiosum  to  this  last 
enlargement,  the  appearance  of  the  inner  surface  of  the 
urethra  is  uniform.  The  membrane  is  thin  and  delicate, 
and  in  a healthy  subject,  who  has  been  free  from  disease 
of  these  parts,  is  of  a whitish  colour;  but  bloodvessels  are 
very  perceptible  in  it.  When  it  is  relaxed,  it  appears  to 
be  thrown  into  longitudinal  wrinkles;  but  it  admits  of 
considerable  extension,  being  somewhat  elastic:  when 
extended,  its  surface  appears  smooth,  as  if  it  were  cover- 
ed with  an  epithelium.  Throughout  the  whole  extent  of 
this  part  of  the  urethra,  are  the  orifices  of  a great  many 
mucous  ducts  or  sinuses,  which  pass  obliquely  back- 
wards from  the  surface.  Many  of  these  are  so  small  that 
they  cannot  be  penetrated  by  a bristle,  or  probe  of  that 
size;  but  some  are  larger.  It  has  not  been  observed  that 
any  glandular  body  immediately  surrounds  them,  al- 
though they  secrete  the  mucus  with  which  the  urethra 
is  lubricated.  On  the  lower  side  of  the  urethra,  near  the 
commencement  of  the  glans  penis,  there  is  one  or  more 
of  them,  so  large  that  their  orifices  sometimes  admit  the 
point  of  a small  bougie. 

These  organs,  when  inflamed,  secrete  the  puriform 
discharge  which  takes  place  in  gonorrhoea.  In  a natural 
state  they  produce  the  mucus  which  is  constantly  spread 
over  the  surface  of  the  urethra,  to  defend  it  from  the  acri- 
mony of  the  urine,  and  which  passes  away  with  that  fluid 
unperceived. 

The  surface  of  the  urethra  is  endued  with  great  sensi- 
bility, and  is  therefore  liable  to  great  irritation  from  con- 
tact with  any  rough  body  or  any  acrid  substance.  Irri- 
tation, thus  excited,  induces  a state  of  contraction,  which 
is  particularly  remarkable,  as  no  muscular  fibres  are  to 
be  seen  in  its  structure.  When  a bougie  has  been  passed 
Vol.  II.  2 A 


186  Contractile  Power  of  the  Urethra. 

into  the  urethra  for  a considerable  distance,  if  it  cannot 
proceed  the  whole  way,  it  sometimes  happens  that  the 
instrument  will  be  discharged  by  a steady  uniform  mo- 
tion, which  seems  to  proceed  from  a progressive  con- 
traction of  the  urethra,  beginning  very  low  down.  At 
particular  times,  after  the  urethra  has  been  much  irritat- 
ed, it  will  not  receive  a bougie,  although  at  other  times 
a bougie  of  equal  size  may  be  passed  to  the  bladder 
without  opposition.  This  cannot  depend  upon  that  elas- 
ticity which  was  noticed  before. 

Upon  the  two  crura  of  the  penis,  or  the  beginning  of  the 
corpora  cavernosa,  are  fixed  the  muscles  called  Erectores 
Penis , which  are  described  in  the  first  volume.*  These 
muscles  cover  the  crura  of  the  penis  from  their  origin  to 
their  junction,  and  not  only  compress  them,  but  also  in- 
fluence the  motion  of  the  penis  when  it  is  distended. 

The  bulb  of  the  urethra  is  covered  by  a muscular  coat, 
called  the  Accelerator  Urinee ,*  which  has  the  effect  of 
driving  forwards  any  fluid  contained  in  the  cavity  of  the 
urethra,  and  also  of  giving  the  same  direction  to  the  blood 
in  that  part  of  the  corpus  spongiosum.  There  is  also 
the  Transversus  Ferine i on  each  side,  that  passes  trans- 
versely from  the  tuberosity  of  the  ischium  to  the  bulb  of 
the  urethra.  Finally  the  lower  part  of  the  sphincter  ani 
muscle,  which  is  nearly  eliptical  in  form,  is  inserted  by 
its  anterior  point  into  the  muscular  covering  of  the  bulb 
of  the  urethra.  Upon  removing  the  integuments,  these 
muscles  are  in  view;  and  the  course  of  the  urethra  from 
the  bladder  is  concealed,  particularly  by  the  anterior 
point  of  the  sphincter  ani.  When  the  sphincter  ani  is  dis- 
sected away  from  its  anterior  connections,  and  the  cel- 
lular and  adipose  substance,  which  is  sometimes  very 
abundant,  is  also  removed,  the  lower  surface  of  the 

* See  description  of  “ Muscles  about  the  Mule  Organs  of  Gene- 
rationVol.  I.  Part  II.  Chap.  II. 


187 


Integuments  of  the  Penis. 

membranous  part  of  the  urethra  may  be  brought  into 
view,  as  it  proceeds  from  the  prostate  gland  to  the  bulb 
of  the  corpus  spongiosum.* 

When  the  accelerator  urinae  is  removed  from  the  bulb 
of  the  urethra,  there  will  appear  two  bodies,  which  have 
some  resemblance  to  flattened  peas.  They  lie  one  on  each 
side  of  the  urethra,  and  communicate  with  its  cavity  by 
means  of  a duct,  which  is  from  one  third  to  half  an  inch 
in  length.  These  are  Cowper’s  glands. 

The  penis  is  connected  to  the  symphysis  pubis  by  a 
ligamentous  substance,  which  proceeds  from  the  back  or 
upper  surface  of  the  organ  to  the  anterior  part  of  the 
symphysis,  and  connects  these  parts  firmly  to  each  other. 

Thus  constructed,  of  the  corpora  cavernosa  and  the 
urethra  with  its  corpus  spongiosum,  and  attached  to  the 
pelvis  as  above  mentioned,  the  penis  is  invested  with  its 
integuments  in  the  following  manner. 

Integuments  of  the  Penis. 

The  glans  penis,  the  structure  of  which  has  been  al- 
ready desctibed,  is  covered  by  a continuation  of  the  skin, 
which  appears  altered  in  its  texture  so  as  to  resemble  in 
some  respects  the  skin  of  the  lips,  and  in  like  manner  is 
covered  by  a delicate  production  of  cuticle. 

Around  the  corona  of  the  glans,  especially  on  its  upper 
part,  there  are  whitish  tubercles,  which  are  of  different 
sizes  in  different  persons,  but  always  very  small.  The 
skin  adheres  firmly  to  the  whole  extent  of  the  corona  of 
the  glans,  and  is  very  delicate  in  its  structure  as  it  con- 

* The  natural  situation  of  the  membranous  part  of  the  urethra, 
and  of  the  prostate  gland,  as  well  as  their  relative  position  with 
respect  to  the  sphincter  ani,  rectum,  &c.  can  be  best  studied  by  a la- 
teral view  of  the  contents  of  the  pelvis;  which  is  to  be  obtained  by 
removing  carefully  one  of  the  ossa  innominata,  and  dissecting  the 
parts  which  were  inclosed  by  it. 


188 


The  Prepuce. 


tinues  from  the  glans  upon  the  body  of  the  penis;  but  it 
gradually  changes,  so  as  to  assume  the  appearance  and 
structure  of  common  skin,  and  continues  in  this  state 
over  the  penis.  The  adhesion  of  the  skin  to  the  ligament- 
ous coat  of  the  corpora  cavernosa  also  becomes  more 
loose,  owing  to  the  quantity  and  texture  of  the  cellular 
substance  which  connects  them.  The  skin  thus  connect- 
ed to  the  penis,  has  commonly  more  length  than  that  or- 
gan, even  in  its  extended  state.  In  consequence  of  this 
greater  length,  and  of  its  adhering  firmly  around  the  co- 
rona glandis,  it  necessarily  forms  a circular  fold  or  plait, 
which  varies  in  size  according  to  the  length  of  the  skin. 
This  fold  is  generally  situated  at  the  commencement  of 
the  firm  attachment  of  the  skin  to  the  body  of  the  penis, 
or  around  the  glans;  but  it  may  be  formed  any  where 
upon  the  body  of  the  penis  by  artificial  management. 

This  duplicature,  or  fold  of  the  skin,  when  it  takes 
place  so  as  to  cover  the  glans,  is  called  the  Prepuce;  and 
the  skin  which  is  very  tender  and  delicate  for  some  dis- 
tance from  the  glans,  forms  that  surface  of  the  prepuce 
which  is  in  contact  with  the  glans  when  it  covers  that 
body. 

There  is  also  a small  fold  of  the  skin,  which  is  longi- 
tudinal in  its  direction,  that  commences  at  the  orifice  of 
the  urethra,  and  extends  backwards,  on  the  lower  sur- 
face of  the  penis.  It  is  unvarying  in  its  position,  and  is 
called  the  Frenum. 

It  is  a general  observation,  that  adepts  is  not  found  in 
the  cellular  substance  which  connects  the  skin  to  the 
body  of  the  penis;  but  this  cellular  substance  is  distended 
with  water  in  some  hydropic  cases. 

From  the  skin  immediately  below  the  glans,  and  from 
small  follicles  on  each  side  of  the  frenum,  is  secreted  an 
unctuous  fluid,  which,  when  allowed  to  continue,  be- 
comes inspissated,  and  acquires  a caseous  consistence 
and  colour,  as  well  as  a peculiar  odour.  It  sometimes 


Bloodvessels  and  Absorbents  of  the  Penis-.  189 

also  acquires  an  acrimony  which  produces  inflammation 
of  the  surface  with  which  it  is  in  contact,  as  well  as  the 
copious  secretion  of  a puriform  fluid. 

The  distribution  of  the  pudic  artery  in  the  penis,  has 
already  been  mentioned;  and  a further  account  of  its  ori- 
gin and  progress  to  its  destination,  will  be  found  in  the 
general  account  of  the  arteries.  Sometimes  small  branches 
of  the  external  pudic  arteries,  which  originate  from  the 
femoral,  are  extended  to  the  penis;  and  it  has  been  as- 
serted, that  branches  of  the  middle  hasmorrhoidal  artery 
have  also  been  found  there,  but  this  does  not  often  occur. 

The  Feins  of  the  penis  are  of  two  kinds:  those  which 
originate  in  the  corpora  cavernosa,  accompany  the  cor- 
responding branches  of  the  pudic  artery,  but  communi- 
cate more  or  less  with  the  plexus  of  veins  on  the  lower 
and  lateral  part  of  the  bladder.  These  is  also  a great  vein 
which  occupies  the  groove  on  the  back  of  the  penis,  be- 
tween the  corpora  cavernosa,  that  appears  particularly 
appropriated  to  the  corpus  spongiosum  urethras;  for  it 
originates  in  the  glans  penis,  and  receives  branches  from 
the  urethra  as  it  proceeds  backwards.  There  are  often  two 
of  these  veins,  one  in  the  groove  and  the  other  more  su- 
perficial: they  generally  unite  near  the  root  of  the  penis. 
The  common  trunk  then  passes  between  the  body  of  the 
penis  and  the  symphysis  pubis,  and  terminates  in  a plexus 
of  veins  at  the  neck  of  the  bladder,  which  is  connected  to 
the  plexus  above  mentioned  on  the  lower  and  lateral  parts 
of  the  same  viscus. 

The  Absorbent  Vessels  of  the  penis  take  two  different 
directions  on  each  side.  Those  which  arise  from  the  in- 
teguments generally,  unite  so  as  to  form  a few  trunks  on 
the  back  of  the  penis,  which  divide  near  the  root  of  the 
organ,  and  proceed  to  the  glands  of  the  groin.  Those 
which  originate  from  the  interior  parts  of  the  penis,  ac- 
company the  bloodvessels,  and  terminate  in  the  plexus 
of  lymphatics  in  the  pelvis. 


190 


Nerves. — General  Observations. 


It  ought  to  be  noted,  that  the  superficial  lymphatics 
generally  enter  the  upper  inguinal  glands. 

The  Nerves  of  the  penis  are  principally  derived  from 
the  lower  sacral  nerves,  which  unite  in  the  plexus  that 
forms  the  great  ischiatic.  From  these  nerves  a branch  on 
each  side  originates,  which  passes,  like  the  pudic  artery, 
between  the  sacro-sciatic  ligaments.  In  this  course  it  di- 
vides into  two  branches,  one  of  which  passes  below  to  the 
muscles  of  the  penis  and  urethra,  and  to  the  contiguous 
parts;  and  some  of  its  branches  seem  finally  to  terminate 
in  the  dartos:  the  other  branch  proceeds  along  the  crura 
of  the  pubis  and  ischium,  and  passing  between  the  sym- 
physis pubis  and  the  body  of  the  penis,  arrives  at  the 
upper  surface  or  dorsum  of  the  penis,  along  which  it  con- 
tinues on  the  outside  of  the  arteries  to  the  glans,  in  which 
it  terminates.  In  this  course  it  sends  off  several  branches, 
some  of  which  terminate  in  the  integuments  of  the  penis. 

After  an  examination  of  the  relative  situation  of  the  mus- 
cles and  bloodvessels  of  the  male  organs  of  generation, 
there  appears  reason  to  doubt,  whether  the  erection  of 
the  penis  can  be  referred  to  pressure  upon  the  veins 
which  return  from  that  organ. — Albinus  has  written  on 
this  subject.  See  Academicarum  Annotationum,  lib.  ii. 
caput  xviii.  Haller  has  also  considered  it,  and  stated  the 
opinions  of  stveral  anatomists,  in  his  Elementa  Phy- 
siologic, tom.  vii.  page  555. 

The  manner  in  which  the  urine  is  confined  in  the  bladder 
does  not  appear  to  be  clearly  understood.  The  con- 
nexion of  the  neck  of  the  bladder  with  the  prostate, 
and  the  appearance  of  the  contiguous  parts  of  the  blad- 
der, do  not  render  it  probable  that  these  parts  act  like 
a sphincter.  The  late  J.  Hunter,  who  paid  great  atten- 
tion to  the  functions  of  these  organs,  was  very  derid- 
ed in  his  opinion  that  the  contraction  of  the  urethra  pro- 
duced the  effect  of  a sphincter  of  the  bladder.  He  has 
published  some  very  ingenious  observations  respecting 
the  manner  in  which  urine  is  discharged  from  the  blad- 


General  Observations. 


191 


der,  in  his  Treatise  on  the  Venereal  Disease,  part  III. 
chapter  IX. 

Mr.  Hunter  also  long  since  asserted,  that  the  vascular 
convoluted  appearance  of  the  corpus  spongiosum  urethrae 
was  more  distinct  in  the  horse  than  the  man.  In  the  fifth 
volume  of  the  Le^ns  d’Anatomie  Comparee  of  Cuvier, 
the  very  learned  and  ingenious  author  confirms  the  de- 
claration of  Hunter,  respecting  the  vascular  convolu- 
tions of  the  corpus  spongiosum  of  the  horse.  He  states, 
that  the  corpora  cavernosa  of  the  penis  of  the  elephant 
appear  to  be  filled  in  a great  degree  with  the  ramifica- 
tions of  veins,  which  communicate  with  each  other  by 
such  large  and  frequent  anastomoses,  that  they  have  a 
cellular  appearance.  A similar  structure  exists  in  the 
horse,  camel,  bullock,  deer,  &c.  and  in  them  all  these 
communicating  branches  can  be  distinguished  from  those 
which  extend  the  whole  length  of  the  penis. 

The  corpus  spongiosum  urethrae,  according  to  M.  Cuvier, 
is  constructed  in  a similar  manner.  From  these  facts  he 
is  induced  to  believe  that  this  structure  pervades  the 
whole  class  of  mammalia. 


192 


CHAPTER  VI. 

OF  THE  FEMALE  ORGANS  OF  GENERATION. 

THE  female  organs  of  generation  consist  of  the  Uterus 
and  Ovaries , with  their  appendages;  and  of  the  Vagina , 
with  the  structure  which  surrounds  its  external  orifice. 
The  uterus  is  situated  in  the  pelvis,  between  the  bladder 
and  rectum;  and  the  ovaries  are  on  each  side  of  it.  The 
vagina  is  a very  large  membranous  canal,  which  passes 
from  tl>e  uretus  downwards  and  forwards,  also  between 
the  bladder  and  rectum,  and  opens  externally. 

Connected  with  the  orifice  of  the  vagina  ar<^  several  bo- 
dies, which  are  called  the  external  parts  of  generation , 
in  order  to  distinguish  them  from  the  uterus  and  ovaries, 
and  their  appendages,  and  also  from  the  canal  of  the  vagi- 
na; which  are  called  the  internal  parts. 

The  bladder  of  urine  lies  above  and  in  contact  with  the 
vagina:  the  urethra  is  also  intimately  connected  with  it. 
The  description  of  the  bladder  and  urethra  is  therefore 
placed  at  the  end  of  this  chapter. 


SECTION  I. 

Of  the  External  Parts  of  Generation. 

The  adipose  membrane,  immediately  anterior  to  the 
symphysis  pubis,  and  on  each  side  of  it,  form  a conside- 
rable prominence  in  females,  which,  at  the  age  of  puber- 
ty, is  covered  with  hair,  as  in  males.  This  prominence 
is  denominated  the  Mons  Veneris. 


Labia  Externa. — Clitoris. 


193 


The  exterior  orifice  commences  immediately  below 
this.  On  each  side  of  this  orifice  is  a prominence  con- 
tinued from  the  mons  veneris,  which  is  largest  above,  and 
gradually  diminishes  as  it  descends.  These  prominences 
have  some  hair  upon  them.  They  are  called  the  Labia 
Externa.  Their  junction  below  is  denominated  the  Four - 
chette.  The  space  between  the  place  of  their  junction  and 
the  anus  is  rather  more  than  an  inch  in  extent,  and  is  de- 
nominated the  Perineum. 

As  the  skin  which  forms  the  labia  is  continued  inter- 
nally, it  becomes  more  thin  and  soft,  and  is  covered  by  a 
more  delicate  cuticle.  It  is  also  more  or  less  florid,  and 
secretes  a peculiar  mucus. 

In  the  upper  angle,  formed  by  the  labia  externa,  is  the 
upper  extremity  and  glans  of  the  clitoris. 

The  Clitoris  is  a body  which  has  a very  strong  resem- 
blance to  the  penis,  but  there  is  no  urethra  attached  to  it. 
It  has  two  crura  of  considerable  length,  which  originate, 
like  those  of  the  penis,  from  the  crura  of  the  pubis  and 
ischium,  and  unite  at  the  symphysis  of  the  pubis  so  as  to 
form  a body,  which  is  not  much  more  than  an  inch  in 
length,  and  is  broad  in  proportion.  The  extremity  of  this 
organ,  called  the  Gians  of  the  Clitoris,  forms  a small 
tubercle,  which  is  covered  above  and  on  the  sides  by  a 
small  plait  or  fold  of  the  skin,  denominated  the  Prepuce. 
These  parts  are  lubricated  by  a secretion  similar  to  that 
which  is  observed  round  the  glans  penis. 

The  crura  of  the  clitoris  have  muscles  similar  to  the 
erectores  penis.  The  interior  structure  of  the  Clitoris  is 
very  similar  to  that  of  the  corpora  cavernosa  of  the  penis, 
or  the  corpus  spongiosum  of  the  urethra.  It  appears  con- 
structed for  a similar  distention,  and  is  endued  with  the 
same  sensibility  as  the  penis.  The  two  lateral  parts  are 
also  separated  from  each  other  by  a septum,  resembling 
that  of  the  penis.  It  is  united  to  the  symphysis  pubis  by 
a ligament. 

Vol.  II.  2 B 


194 


JVympha. — Hymen. 

The  Prepuce  of  the  clitoris  has  a semicircular  form: 
below  its  extremities  two  folds  or  plaits  commence,  one 
on  each  side,  which  are  situated  obliquely  with  respect 
to  each  other,  so  as  to  form  an  angle.  These  folds  are 
denominated  the  JVymphte. 

The  Nymplice  extend  from  the  clitoris  downwards 
nearly  as  far  as  the  middle  of  the  orifice  of  the  vagina. 
They  are  situated  within  the  external  labia,  and  are 
formed  by  the  skin  after  it  has  become  more  delicate  in 
its  texture.  Their  surface  however  is  often  somewhat 
corrugated.  There  are  many  bloodvessels  in  their  inter- 
nal structure,  and  it  is  supposed  they  are  occasionally 
somewhat  tumid.  They  are  fiat,  and  their  exterior  edge 
is  convex:  so  that  they  are  narrow  at  their  extremities, 
and  broad  in  the  middle.  Their  breadth  is  very  variable, 
and  in  some  instances  is  great.  In  a majority  of  cases  it  is 
equal  to  one  fourth  of  their  length.  Their  colour  in  young 
subjects  is  of  a bright  red;  in  women  advanced  in  years 
and  who  have  had  many  children,  they  are  of  a brown 
red,  and  sometimes  of  a dark  colour. 

The  use  of  these  parts  is  not  very  evident.  They  have 
been  supposed  to  regulate  the  course  of  the  urine  as  it 
flows  from  the  urethra,  but  their  effect  in  this  respect  is 
not  great.  They  have  also  been  supposed  to  favour  the 
necess.  ry  enlargement  of  the  parts  in  parturition. 

The  orifice  of  the  urethra  is  situated  about  an  inch  and 
one  quarter  further  inward  than  the  clitoris.  It  is  often 
rather  less  than  the  diameter  of  the  urethra,  and  is  some- 
what protuberant.  The  orifices  of  mucous  ducts  are  to  be 
perceived  around  it. 

The  orifice  of  the  urethra  is  at  the  commencement  of 
the  canal  of  the  vagina.  Immediately  within  this  orifice 
is  situated  the  membrane  denominated  Hymen . 

The  Hymen  is  an  incomplete  septum,  made  by  a fold 
or  duplicature  of  the  membrane  which  forms  the  surface 
contiguous  to  it.  Sometimes  it  is  circular,  with  an  aper- 


195 


The  Vagina. 

ture  in  the  center.  Sometimes  it  has  a resemblance  to  the 
crescent,  the  aperture  being  at  the  upper  part  of  it.  The 
hymen  has  frequently  been  found  without  a perforation, 
and  has  therefore  prevented  the  discharge  of  the  men- 
strual evacuation.  It  is  generally  ruptured  in  the  first  in- 
tercourse of  the  sexes;  and  some  small  tubercles,  which 
are  found  on  the  surface  of  the  vagina  near  the  spot  where 
it  was  situated,  are  supposed  to  be  the  remains  of  it. 
These  tubercles  are  called  Carunculce  Myrtijormes. 


SECTION  II. 

Of  the  Vagina. 

THE  canal  of  the  vagina,  commencing  at  the  hymen 
and  the  orifice  of  the  urethra,  is  rather  more  narrow  at 
its  beginning  than  it  is, further  inward.  From  this  place  it 
extends  backwards  and  upwards,  and  partakes  in  a small 
degree  of  the  curve  of  the  rectum:  while  the  bladder, 
which  is  above  it,  and  rests  upon  it,  increases  the  curva- 
ture of  the  anterior  part.  It  is  much  larger  in  women  who 
have  had  children  than  in  those  who  have  not. 

The  membrane  which  lines  the  vagina  resembles,  to  a 
certain  degree,  the  membranes  which  secrete  mucus  in 
different  parts  of  the  body.  Its  surface  appears  to  consist 
of  very  small  papillae;  and  at  the  anterior  extremity  of  the 
vagina  it  forms  a great  number  of  rugae,  which  are  ar- 
ranged in  a transverse  direction,  both  on  the  part  of  the 
vagina  connected  to  the  bladder,  and  on  that  which  is 
connected  to  the  rectum,  while  the  lateral  parts  of  the  va- 
gina are  smooth.  These  rugae  are  most  prominent  in  the 
middle;  so  that  a raised  line  appears  to  pass  through  them 
at  right  angles,  This  line  extends  from  without  inwards. 
The  rugae  on  the  part  next  to  the  bladder  are  the  strongest. 


196  Corpora  Cavernosa. — Sphincter  Vagina \ 

This  arrangement  of  the  surface  of  the  vagina  does  not 
extend  beyond  the  external  half  of  the  canal:  on  the  in- 
ternal half  part,  or  that  nearest  the  uterus,  the  surface  is 
smooth. 

The  rugae  are  considerably  diminished  in  tvomen  who 
have  had  children. 

Throughout  this  surface  are  to  be  seen,  in  some  cases 
with  the  naked  eye,  the  orifices  of  mucous  follicles  or 
ducts,  which  occasionally  discharge  considerable  quanti- 
ties of  mucus. 

Exterior  to  this  lining  membrane  of  the  vagina  is  a 
dense  cellular  structure,  which  has  not  yet  been  com- 
pletely investigated:  it  is  of  a lightish  colour,  and  has 
some  resemblance  to  the  texture  of  the  body  of  the  ute- 
rus. It  is  very  vascular,  and  appears  to  be  of  a fibrous 
structure.  It  may  be  very  much  distended,  and  seems 
to  have  a contractile  power. 

At  the  anterior  extremity  of  the  vagina,  on  each  side 
of  it,  there  is,  superadded  to  this,  a cellular  or  vascular 
substance,  from  eight  lines  to  an  inch  in  breadth;  which, 
when  cut  into,  resembles  the  corpora  cavernosa,  or  the 
corpus  spongiosum  of  the  penis.  These  bodies  com- 
mence near  the  body  of  the  clitoris,  and  extend  down- 
wards on  each  side  of  the  vagina.  They  have  been  called 
Plexus  Ret  ef or  mis,  and  Corpora  Cavernosa  V igina,  and 
are  supposed  to  be  occasionally  distended  with  blood, 
like  the  clitoris  and  penis. 

These  corpora  cavernosa  are  covered  by  muscular  fi- 
bres, which  pass  over  them  on  each  side  from  the  sphinc- 
ter ani  to  the  body  of  the  clitoris;  to  each  of  which  organs 
they  are  attached.  These  fibres  constitute  the  sphincter 
vaginae  muscle,  and  contract  the  diameter  of  the  vagina 
at  the  place  where  they  are  situated. 

The  transversus  perinei  muscles  also  exist  in  the  fe- 
male. They  pass  from  the  tuberosities  of  the  ischia,  and 
are  inserted  into  ^ dense  whitish  substance  in  the  perine- 


Unimpregnated  Uterus.  197 

um,  to  which  the  anterior  extremity  of  the  sphincter  ani 
is  likewise  attached. 

The  vagina  is  in  contact  with  the  rectum  behind;  the 
bladder  lies  upon  it  and  anterior  to  it.  A small  portion  of 
peritoneum,  to  be  reflected  to  the  rectum,  is  continued 
from  the  uterus  upon  the  posterior  part  of  it.  The  lateral 
portions  of  it  are  invested  with  cellular  substance.  The 
anterior  extremity  of  the  uterus,  which  is  called  the  Os 
Tincse,  projects^nto  it  from  above. 


SECTION  III. 

Of  the  Uterus , the  Ovaries  and  their  Appendages. 

The  Uterus 

HAS  been  compared  to  a pear  with  a long  neck.  There 
is  of  course  a considerable  difference  between  the  body 
and  neck;  the  first  being  twice  as  broad  as  the  last.  Each 
of  these  parts  is  somewhat  flattened. 

In  subjects  of  mature  age,  who  have  never  been  preg- 
nant, the  whole  of  the  uterus  is  about  two  inches  and  a 
half  in  length,  and  more  than  one  inch  and  a half  in  breadth 
at  the  broadest  part  of  the  body:  it  is  also  near  an  inch  in 
thickness. 

It  is  generally  larger  than  this  in  women  who  have 
lately  had  children. 

The  uterus  is  situated  in  the  pelvis  between  the  blad- 
der and  rectum,  and  is  inclosed  in  a duplicature  or  fold  of 
the  peritoneum,  which  forms  a loose  septum  that  extends 
from  one  side  of  the  pelvis  to  the  other,  and  divides  it 
into  an  anterior  and  posterior  chamber.  The  posterior 
surface  of  this  septum  is  opposed  to  the  rectum,  and  the 
anterior  to  the  bladder.  The  two  portions  of  this  septum, 


198  Ligaments  of  the  Uterus. 

which  are  between  the  uterus  and  the  lateral  parts  of  the 
pelvis,  are  called  the  Broad  Ligaments. 

On  the  posterior  surface,  the  Ovaries  are  situated  on 
each  side  of  the  uterus,  being  inclosed  by  a process  of  the 
ligament  or  septum.  Above  them,  in  the  upper  edge  of 
the  septum,  are  the  Fallopian  Tubes , which  are  ducts  that 
commence  at  the  upper  part  of  the  uterus  on  each  side, 
and  proceed  in  a lateral  direction  for  some  distance,  when 
they  form  an  angle  and  incline  downwards  to  the  ovaries. 
These  ducts  are  inclosed  between  the  two  laminae  of  the 
septum  for  the  greater  part  of  their  length. 

The  peritoneum,  which  forms  the  septum,  is  reflected 
from  it,  posteriorly,  to  the  rectum  and  the  posterior  sur- 
face of  the  pelvis,  and  anteriorly,  to  the  bladder.  In  its 
progress,  in  each  direction,  it  forms  small  plaits  or  folds; 
two  of  which  extend  from  the  uterus  to  the  rectum  pos- 
teriorly, and  two  more  to  the  bladder  anteriorly:  these 
are  called  the  Anterior  and  Posterior  Ligaments  of  the 
Uterus. 

The  other  ligaments,  which  proceed  more  immediately 
from  the  uterus,  are  called  the  Bound  Ligaments.  These 
arise  from  each  side  of  the  uterus,  at  a small  distance  be- 
fore and  below  the  origins  of  the  fallopian  tubes,  and  pro- 
ceed in  an  oblique  course  to  the  abdominal  rings.  These 
ligaments  are  also  invested  by  the  peritoneum.  They  pass 
through  the  rings  and  soon  terminate. 

In  the  body  of  the  uterus  is  a cavity  which  approaches 
to  the  triangular  form;  and  from  which  a canal  proceeds 
through  its  neck.  This  cavity  is  so  small  that  its  sides 
are  almost  in  contact,  and  the  canal  is  in  proportion;  so 
that  this  organ  is  very  thick  in  proportion  to  its  bulk. 

The  substance  of  which  the  uterus  consists  is  very  firm 
and  dense:  it  is  of  a whitish  colour,  with  a slight  tinge  of 
red.  There  are  many  bloodvessels,  with  nerves  and  ab- 
sorbent vessels,  in  its  texture.  The  nature  and  structure 
of  this  substance  has  not  yet  been  precisely  ascertained. 


199 


Structure  and  Cavity  of  the  Uterus. 

It  appears  very  different  indeed  from  muscle;  but  the 
uterus  occasionally  contracts,  with  great  force,  during  la- 
bour.  It  is  not  rendered  thin  by  its  enlargement  during 
pregnancy,  and  the  bloodvessels  in  its  texture  are  greatly 
enlarged  at  that  time. 

Exteriorly,  the  uterus  is  covered  by  the  peritoneum,  as 
has  already  been  mentioned.  Internally  it  is  lined  with  a 
delicate  membrane  that  has  some  resemblance  to  those 
which  secrete  mucus,  and  is  generally  of  a whitish  co- 
lour, abounding  with  small  orifices  that  can  be  seen  with 
a magnifying  glass.  This  membrane  is  so  intimately  con- 
nected to  the  substance  of  the  uterus  that  some  anatomists 
have  supposed  it  was  merely  the  internal  surface  of  that 
substance,  but  this  opinion  is  now  generally  abandoned. 
It  is  supposed  that  the  colour  of  this  membrane  is  more 
florid  about  the  period  of  menstruation. 

The  cavity  of  the  uterus,  as  has  been  observed  before, 
is  triangular  in  form.  When  the  organ  is  in  its  natural 
position,  the  upper  side  of  this  triangle  is  transverse  with 
respect  to  the  body,  and  the  other  sides  pass  downwards 
and  inwards.  In  each  of  the  upper  angles  are  the  orifices 
of  the  fallopian  tubes,  which  are  of  such  size  as  to  admit 
a hog’s  bristle. 

The  two  lower  lines  of  the  triangle  are  slightly  curved 
outwards  at  their  upper  extremities;  so  that  the  upper  an- 
gles of  the  triangle  project  outwards,  and  the  orifices  of 
the  fallopian  tubes  are  nearer  to  the  external  surface  than 
they  otherwise  would  be. 

The  lower  angle  of  the  cavity  of  the  uterus  is  occupied 
by  the  orifice  of  the  canal,  which  passes  through  the  neck 
of  the  organ;  this  orifice  is  from  three  to  four  lines  in  di- 
ameter. The  canal  is  about  an  inch  in  length,  and  is  rather 
wider  in  the  middle  than  at  either  end.  On  the  anterior 
and  posterior  portions  of  its  surface  are  many  small  ridges 
which  have  an  arborescent  arrangement,  one  large  ridge 
passing  internally  from  the  commencement  of  the  canal, 


200  Structure  of  the  Fallopian  Tubes. 

from  which  a number  of  other  ridges  go  off  in  a transverse 
direction.  These  ridges  extend  nearly  the  whole  length 
of  the  canal.  In  the  grooves,  between  the  ridges,  are  the 
orifices  of  many  mucous  ducts.  There  are  also  on  this 
surface  a number  of  transparent  bodies  of  a round  form, 
equal  in  bulk  to  a middle  sized  grain  of  sand;  the  nature 
and  use  of  which  is  unknown.  They  have  been  called 
Ovula  JYabothi , after  a physiologist,  who  published  some 
speculations  respecting  their  use,  about  the  commence- 
ment of  the  last  century. 

The  canal  of  the  neck  of  the  uterus  is  very  different 
from  other  ducts,  for  it  seems  to  be  a part  of  the  cavity 
to  which  it  leads,  and  when  the  cavity  of  the  uterus  be- 
comes enlarged  in  the  progress  of  pregnancy,  this  canal . 
is  gradually  converted  into  a part  of  that  cavity. 

The  lower  extremity  of  the  neck  of  the  uterus  is  irre- 
gularly convex  and  tumid.  The  orifice  of  the  canal  in  it  is 
oval,  and  so  situated  that  it  divides  the  convex  surface  of 
the  neck  into  two  portions,  which  are  called  the  Lips. 
The  anterior  or  upper  portion  is  thicker  than  the  other. 

This  extremity  of  the  uterus  protrudes  into  the  vagina, 
and  is  commonly  called  Os  Tinea.  As  the  anterior  por- 
tion or  lip  is  larger  and  more  tumid  than  the  posterior,, 
the  vagina  extends  further  beyond  the  os  tincat  on  the 
posterior  part  than  on  the  anterior. 

The  Fallopian  Tubes 

Are  two  canals,  from  four  to  five  inches  in  length, 
which  proceed  between  the  laminae  of  the  broad  liga- 
ments, from  the  upper  angles  of  the  uterus,  in  a trans- 
verse direction,  to  some  distance  from  the  uterus,  when 
they  form  an  angle,  and  take  a direction  downwards  to- 
wards the  ovaries. 

They  are  formed,  for  a considerable  part  of  their  extent, 
by  a substance  which  resembles  that  of  which  the  uretus 


201 


Situation  of  the  Ovaries . 

consists,  and  are  lined  by  a membrane  continued  from  the 
internal  membrane  of  the  uterus.  Their  extremities  ap- 
pear to  be  composed  of  membrane,  which  is  rendered  flo- 
rid by  the  bloodvessels  in  its  texture.  At  the  commence- 
ment their  diameters  are  extremely  small;  but  they  en- 
large in  their  progress.  This  enlargement  is  gradual  for 
the  first  half,  and  afterwards  sudden;  the  enlarged  part  is 
more  membranous  than  the  small  part,  and  has  a bright 
red  colour.  The  large  extremity  is  loose  in  the  cavity  of 
the  pelvis,  and  is  not  invested  by  the  laminae  of  the  broad 
ligaments.  Near  the  termination  the  diameter  is  often 
contracted;  after  which  the  membrane  which  forms  the 
tube  expands  into  an  open  mouth,  the  margin  of  which 
consists  of  fringed  processes:  this  margin  is  also  oblique, 
as  respects  the  axis  of  the  tube;  and  the  different  fringed 
processes  are  not  all  of  the  same  length;  but  the  longest 
are  in  the  middle,  and  the  other  regularly  diminish  on  each 
side  of  them:  these  processes  constitute  the  Fimbria  of 
the  fallopian  tubes. 

The  internal  surface  of  the  large  extremities  of  these 
tubes  is  extremely  vascular;  and  there  are  some  longitu- 
dinal  fibres  of  a red  colour  to  be  seen  on  it. 

The  Round  Ligaments , 

Which  have  already  been  mentioned,  are  cords  of  a 
fibrous  structure,  with  many  bloodvessels  in  them.  They 
arise  from  the  uterus  below  the  origin  of  the  fallopian 
tubes,  and  proceed  under  the  anterior  lamina  of  the  broad 
ligament  to  the  abdominal  rings,  through  which  they  pass; 
and  then  the  fibres  and  vessels  are  expanded  upon  the 
contiguous  cellular  substance. 

The  Ovaries 

Are  two  bodies  of  a flattened  oval  form;  one  of  which 
is  situated  on  each  side  of  the  uterus  on  the  posterior  sur- 
Vol.  II.  2 C 


202  Structure  of  the  Ovaries.  Corpora  Lutea. 

face  of  the  broad  ligament,  and  invested  completely  by  a 
process  of  the  posterior  lamina,  which  forms  a coat,  and 
also  a ligament  for  it.  The  size  of  this  organ  varies  indif- 
ferent subjects,  but  in  a majority  of  those  who  are  about 
the  age  of  maturity  it  is  between  ten  and  twelve  lines  in 
length.  It  is  connected  to  the  uterus  by  a small  ligament, 
or  bundle  of  fibres  of  the  same  structure  with  the  round 
ligaments,  which  is  not  more  than  two  lines  in  diameter, 
and  is  included  between  the  laminag  of  the  broad  liga- 
ment. 

The  process  of  the  broad  ligament  forms  an  external 
coat  to  the  ovary;  within  this  is  the  proper  coat  of  the  or- 
gan, which  is  a firm  membrane.  This  membrane  is  so 
firmly  connected  to  the  substance  of  the  ovary  which  it 
incloses,  that  it  cannot  be  easily  separated  from  it.  The 
ovary  is  of  a whitish  colour  and  soft  texture,  and  has 
many  bloodvessels.  In  virgins  of  mature  age  it  contains 
from  ten  to  twenty  vesicles,  formed  of  a delicate  mem- 
brane, filled  with  a transparent  coagulable  fluid.  Some 
of  these  vesicles  are  situated  so  near  to  the  surface  of  the 
ovary  that  they  are  prominent  on  its  surface;  others  are 
near  the  center.  They  are  very  different  in  size;  the  largest 
being  between  two  and  three  lines  in  diameter,  and  others 
not  more  than  one  third  of  that  size. 

In  women  who  have  had  children,  or  in  whom  concep- 
tion has  taken  place,  some  of  these  vesicles  are  removed; 
and  in  their  place  a cicatrix  is  found. 

It  has  been  ascertained,  that  during  the  sexual  inter- 
course with  males,  one  of  these  vesicles,  which  was  pro- 
tuberant on  the  surface,  is  often  ruptured,  and  a cavity  is 
found.  A cicatrix  is  soon  formed,  where  the  membrane 
was  ruptured;  and  in  the  place  occupied  by  the  vesicle 
there  is  a yellow  substance  denominated  Corpus  Luteum. 
This  corpus  luteum  generally  continues  until  the  middle 
@f  pregnancy:  it  often  remains  during  that  state,  and  for 


Arteries  of  the  Uterus.  203 

some  time  after  delivery,  but  it  gradually  vanishes.  The 
cicatrization  continues  during  life. 

In  many  cases  these  cicatrices  correspond  with  the 
number  of  conceptions  which  have  taken  place;  but  they 
often  exceed  the  number  of  conceptions,  and  they  have 
been  found  in  cases  where  conception  has  not  been  known 
to  have  taken  place. 

In  very  old  subjects,  where  conception  has  never  taken 
place,  the  vesicles  are  either  entirely  removed,  or  small 
dense  tubercles  only  remain  in  their  place. 

The  Arteries 

Of  the  uterus  are  derived  from  two  very  different 
sources;  viz.  from  the  spermatic  and  from  the  hypogas- 
tric arteries. 

The  spermatic  arteries,  instead  of  passing  directly  down 
to  the  abdominal  ring,  proceed  between  the  laminae  of  the 
broad  ligament,  and  send  branches  to  the  ovaries,  which 
may  sometimes  be  traced  to  the  vesicles.  They  also  send 
branches  to  the  fallopian  tubes  and  to  the  uterus.  Those 
which  are  on  the  opposite  sides  of  the  uterus  anastomose 
with  each  other,  and  also  with  the  branches  of  the  hypo- 
gastric arteries.  There  are  also  branches  of  these  arteries 
in  the  round  ligaments,  which  accompany  them  to  their 
termination  outside  of  the  abdominal  ring. 

The  principal  arteries  of  the  uterus  are  those  derived 
from  the  hypogastric,  which  sends  to  each  side  of  it  a 
considerable  branch,  called  the  Uterine . This  vessel 
leaves  the  hypogastric  very  near  the  origin  of  the  internal 
pudic,  and  proceeds  to  the  cervix  of  the  uterus:  it  passes 
between  the  lamina?,  of  the  broad  ligaments,  and  sends 
branches  to  the  edge  of  the  uterus,  which  penetrate  its 
texture.  The  branches  which  are  in  the  texture  of  the 
uterus  are  very  small  indeed,  in  young  subjects.  In  wo- 
men who  have  bad  children  they  are  considerably  larger; 


204  Veins  of  the  Uterus.  Lymphatics. 

but  during  pregnancy  they  gradually  enlarge  with  the 
growth  of  the  uterus,  and  become  very  considerable. 
The  se  arteries  observe  a serpentine  and  peculiarly  tor- 
tuous course.  Those  on  the  opposite  sides  anastomose 
with  each  other. 

The  Veins 

Of  the  uterus,  like  the  arteries,  form  spermatic  and 
uterine  trunks.  The  Spermatic  Vein  is  much  larger  than 
the  artery.  It  ramifies  as  in  males,  and  forms  a very 
large  plexus,  which  constitutes  the  corpus  pampiniforme. 
Many  of  the  veins  which  form  this  body,  originate  near 
the  ovary:  a considerable  number  also  come  from  the  fal- 
lopian tubes  and  the  uterus.  The  spermatic  vein  and  its 
branches  are  greatly  enlarged  indeed  during  pregnancy; 
and  it  is  said  that  they  are  enlarged  the  same  way  during 
the  menstrual  discharge. 

The  most  important  veins  of  the  uterus  are  the  branches 
of  the  Uterine  V ei ns.  They  are  extremely  numerous,  and 
form  a plexus  on  the  side  of  the  uterus;  from  which  two 
or  more  uterine  veins  proceed  in  the  course  of  the  artery, 
and  join  the  hypogastric.  These  veins  also  are  greatly  en- 
larged during  pregnancy. 

The  Lymphatic  Vessels 

Of  the  uterus,  and  its  appendages,  are  very  numerous. 
In  the  unimpn  gnated  state  they  are  small;  but,  during 
pregnancy,  they  increase  greatly.  They  proceed  from  the 
uterus  in  very  different  directions.  Some  that  accompany 
the  round  ligaments  go  to  the  lymphatic  glands  of  the 
groin.  Others  which  take  the  course  of  the  uterine  blood- 
vessels pass  to  glands  in  the  pelvis,  and  a third  set  follow 
the  spermatic  arteries  and  veins  to  the  glands  on  the  loins. 


Bladder  and  Urethra. 


205 


The  Nerves 

Of  the  ovaries  are  derived  from  the  renal  plexus,  and 
those  of  the  uterus  and  vagina  from  the  hypogastric 
plexus,  or  the  lower  portions  of  the  sympathetic,  and  the 
third  and  fourth  sacral  nerves. 


SECTION  III. 

Of  the  Bladder  and  Urethra. 

The  situation  of  the  Bladder , as  respects  the  symphy- 
sis pubis,  is  nearly  alike  in  both  sexes;  but  that  part  of 
it  which  is  immediately  behind  the  insertion  of  the  ure- 
ters is  rather  lower  in  males  than  in  females.  The  bottom 
of  the  bladder  rests  upon  the  upper  part  of  the  vagina,  a 
thin  stratum  of  cellular  substance  only  intervening:  when 
that  viscus  is  distended  it  forms  a tumor,  which  com- 
presses the  vagina. 

The  ureters  are  inserted,  and  the  urethra  commences 
in  the  same  part  of  the  bladder,  in  both  sexes. 

The  length  of  the  Urethra  is  between  one  and  two 
inches.  When  the  body  is  in  a direct  position,  it  is  nearly 
horizontal;  but  it  is  slightly  curved,  with  its  convexity 
downwards.  It  is  immediately  above  the  vagina,  and  it 
passes  below  the  body  of  the  clitoris.  The  external  ori- 
fice of  it  is  rather  more  than  an  inch  within  the  glans  or 
head  of  the  clitoris.  This  orifice  is  somewhat  prominent 
in  the  vagina. 

In  the  internal  or  lining  membrane  of  the  urethra  there 
are  many  orifices  of  mucous  follicles,  and  also  longitudi- 
nal wrinkles,  as  in  the  urethra  of  males.  The  diameter  of 
the  female  urethra  and  its  orifice  in  the  bladder  are  greater 
than  they  are  in  the  male.  For  this  reason  it  has  been 


206  Gradual  Change  in  the  Gravid  Uterus . 

supposed,  that  women  are  less  liable  to  calculus  of  the 
bladder  than  men.* 

The  urethra  is  intimately  connected  with  the  external 
coat  of  the  vagina,  and  between  them  there  is  a spongy 
cellular  substance  which  makes  the  rough  surface  of  the 
vagina  prominent;  so  that  the  urethra  has  been  supposed, 
although  erroneously,  to  be  invested  with  the  prostate. 
It  is  capable  of  great  artificial  dilatation. 

Of  the  Changes  induced  in  the  Uterus  in  the  progress  of 
Pregnancy. 

The  alteration  which  takes  place  in  the  size  of  the  ute- 
rus during  pregnancy  is  truly  great.  About  the  conclu- 
sion of  that  period,  instead  of  the  small  body  above  de- 
scribed, which  is  almost  solid,  the  uterus  forms  an  im- 
mense sac,  which  extends  from  the  termination  of  the 
vagina  in  the  pelvis,  into  the  epigastric  region;  and  from 
one  side  of  the  abdomen  to  the  other;  preserving,  how- 
ever, an  ovoid  figure. 

This  change  is  so  gradual  at  first,  that  the  uterus  does 
not  extend  beyond  the  cavity  of  the  pelvis  before  the  third 
month,  although  at  the  end  of  the  seventh  month  it  is  very 
near  the  epigastric  region. 

For  the  first  six  months  the  body  of  the  uterus  appears 
principally  concerned  in  the  enlargement:  after  this  the 
cervix  begins  to  change,  and  is  gradually  altered,  so  as  to 
compose  a portion  of  the  sac,  rather  of  less  thickness  than 
the  rest  of  the  uterus;  the  mouth  being  ultimately  an  aper- 
ture in  a part  which  is  much  thinner  than  the  other  por- 
tions of  the  organ.  _ 

The  change  which  takes  place  in  the  texture  of  some 
of  the  appendages  of  the  uterus  is  very  important. 

The  Broad  Ligaments,  which  seem  particularly  calcu- 
lated to  favor  the  extension  of  the  uterus,  are  necessarily 

* It  has  however  been  asserted  that  they  are  also  less  liable  to 
calculi  in  the  kidneys. 


General  Observations. 


207 


altered  by  the  change  in  the  size  of  that  organ,  but  not  en- 
tirely done  away.  The  portion  of  peritoneum  of  which 
they  are  formed  must  be  very  much  enlarged  with  the 
growth  of  the  uterus,  as  it  continues  to  cover  it.  The 
Round  Ligaments  are  much  elongated;  and  they  observe 
a more  straight  course  to  the  abdominal  ring.  The  Fallo- 
pian Tubes  are  enlarged;  and  instead  of  passing  off  late- 
rally from  the  uterus,  they  now  proceed  downwards  by 
the  side  of  it.  The  Ovaries  appear  rather  larger  and  more 
spongy:  their  relative  situation  is  necessarily  lower. 

The  change  in  the  Uterus  itself  is  particularly  interest- 
ing. The  great  increase  of  its  size  is  not  attended  with 
any  considerable  diminution  of  thickness  in  its  sub- 
stance; nor  are  the  arteries  much  less  convoluted  than  be- 
fore pregnancy,  as  might  have  been  expected.  They  are 
greatly  enlarged  in  diameter,  and  the  orifices  of  the  exha- 
lent  vessels  on  the  internal  surface  of  the  uterus  are  much 
more  perceptible. 

The  veins  are  much  more  enlarged  than  the  arteries., 
and  in  some  places  appear  more  than  half  an  inch  in  dia- 
meter. They  are  not  regularly  cylindrical,  but  rather  flat. 
They  anastomose  so  as  to  form  an  irregular  net  work. 

The  uterus  appears  much  more  fibrous  and  muscular 
in  the  gravid  than  in  the  unimpregnated  state.  The  con- 
tractile power  of  the  gravid  uterus  is  not  only  proved  by 
the  expulsion  of  its  contents,  but  also  by  very  vigorous 
contractions,  which  are  occasionally  observed  by  accou- 
cheurs. 

Although  the  general  effects  which  result  from  the  par- 
ticular conditions  of  the  uterus  in  pregnancy,  menstru- 
ation, &c.  evince  that  the  influence  of  this  organ  upon 
the  whole  system  is  very  great,  yet  it  seems  probable 
that  the  sexual  peculiarities  of  females  are  especially 
dependent  upon  the  ovaria. 

This  sentiment  is  confirmed  by  an  account  of  a wo- 
man in  whom  the  ovaria  were  deficient,  which  is  pub- 


208 


Peculiarity  of  the  Female  Hottentots. 

lished  in  the  London  Philosophical  Transactions  for 
1805,  by  Mr.  C.  Pears.  The  subject  lived  to  the  age  of 
twenty  nine  years.  She  ceased  to  grow  after  the  age  of 
ten  years,  and  therefore  was  not  more  than  four  feet 
six  inches  in  height:  her  breadth  across  the  hips  was 
but  nine  inches,  although  the  breadth  of  the  shoulders 
was  fourteen.  Her  breasts  and  nipples  never  enlarged 
more  than  they  are  in  the  male  subject.  There  was 
no  hair  on  the  pubes,  nor  were  there  any  indications  of 
puberty  in  mind  or  body.  She  never  menstruated.  At 
the  age  of  twenty-nine  she  died  of  a complaint  in  the 
breast,  attended  with  convulsions.  The  uterus  and  os 
tincae  were  found  not  increased  beyond  their  usual  size 
during  infancy.  The  cavity  of  the  uterus  was  of  the 
common  shape,  but  its  coats  were  membran  us.  The 
Fallopian  Tubes  were  pervious.  “ The  Ovaria  -were  so 
indistinct  that  they  rather  showed  the  rudiments  which 
ought  to  have  formed  them , than  any  part  of  the  natural 
structured'’ 

Another  case,  which  confirms  the  aforesaid  sentiment, 
is  related  in  one  of  the  French  periodical  publications. 

It  has  been  long  known  that  a race  of  savages  near  the 
Cape  of  Good  Hope  were  distinguished  from  the  gene- 
rality of  their  species  by  a peculiarity  about  the  puden- 
dum. An  account  of  this  structure  has  been  given  with 
some  precision  by  Messrs.  Peron  and  Lesueur,  in  a 
paper  which  was  read  to  the  National  Institute  of  France. 
It  is  a flap  or  apron,  four  inches  in  length,  which  is 
united  to  the  external  labia  near  their  upper  angle,  and 
hangs  down  before  the  clitoris  and  the  external  orifice 
of  the  parts  of  generation.  It  is  divided  below  into  two 
lobes,  which  cover  the  orifice.  It  is  formed  by  a soft 
distensible  skin,  free  from  hair,  which  is  occasionally 
corrugated  like  the  scrotum,  and  is  rather  more  florid 
than  the  ordinary  cutis.* 

* This  paper  has  not  yet  been  published  by  the  Institute,  but  it  is 
referred  to  by  M.  Cuvier  in  his  Le$ons  d’Anatomie  Comparee, 
vol.  v.  page  1 24. — Messrs.  Peron  and  Lesueur  were  naturalists  who 
accompanied  captain  Baudin  in  his  voyage  of  discovery. 


Peculiarities  in  the  Abdomen  of  the  Foetus.  209 


The  Abdomen  of  the  Foetus. 

The  difference  between  the  fetus  and  the  adult,  in  the 
cavity  of  the  abdomen,  is  very  conspicuous  at  the  first 
view. 

The  Liver  in  the  fetus  is  so  large  that  it  occupies  a 
very  considerable  part  of  the  abdomen.  Its  left  lobe,  which 
is  larger  in  proportion  than  the  right,  extends  far  into  the 
left  hypochondriac  region. 

The  Bladder  of  urine,  when  filled,  extends  from  tile 
cavity  of  the  pelvis  a considerable  distance  towards  the 
umbilicus;  so  that  the  greatest  part  of  it  is  in  the  cavity 
of  the  abdomen.  A ligament  of  a conical  figure  extends 
from  the  center  of  the  upper  part  of  the  bladder  to  the 
umbilicus;  with  an  artery  on  each  side  of  it,  which  is  soon 
to  be  described.  This  ligament,  which  is  in  the  situation 
of  the  urachus  of  the  fetus  of  quadrupeds,  is  hollow,  and 
thus  frequently  forms  a canal,  which  has  a very  small 
diameter,  that  communicates  with  the  bladder  by  an  aper- 
ture still  smaller,  and  continues  a short  distance  from  the 
bladder  towards  the  umbilicus.  In  a few'  rare  instances 
this  canal  has  extended  to  the  umbilicus,  so  that  urine  has 
been  discharged  through  it,  but  the  ligament  is  commonly 
solid  there. 

The  Stomach  appears  to  be  more  curved  in  the  fetus 
than  in  the  adult. 

The  Great  Intestine  does  not  extend  sufficiently  far,  be- 
yond the  insertion  of  the  ileon,  to  form  the  caecum  com- 
pletely. 

The  Glandules  Renales  are  much  larger  in  proportion 
in  the  foetus  than  in  the  adult.  The  colour  of  the  fluid 
they  contain  is  more  florid. 

The  Kidneys  are  lobulated. 

The  Testicles  in  the  fetus  are  found  above  the  pelvis, 
in  the  lumbar  region,  behind  the  peritoneum,  until  two 
Voi.  II.  2 D 


210 


Descent  of  the  Testicle  in  the  Foetus. 

months  before  birth.  Thus  situated,  their  bloodvessels  and 
nerves  proceed  from  sources  which  are  near  them;  but  the 
vas  deferens,  being  connected  to  the  vesiculae  seminales 
by  one  extremity,  is  necessarily  in  a very  different  situa- 
tion from  what  it  is  in  the  adult:  it  proceeds  from  the  tes- 
ticle downwards  to  the  neck  of  the  bladder. — While  each 
testicle  is  in  this  situation,  it  is  connected  with  a sub- 
stance or  ligament,  called  Gubernaculum,  of  a conical  or 
pyramidical  form,  attached  to  its  lower  end,  and  extends 
from  it  to  the  abdominal  ring.  This  substance  is  vas- 
cular, and  of  a fibrous  texture:  its  large  extremity  ad- 
heres to  the  testicle,  its  lower  and  small  extremity- 
passes  through  the  abdominal  ring,  and  appears  to  ter- 
minate in  the  cellular  substance  exterior  to  that  open- 
ing, like  the  round  ligament  in  females.  The  Guber- 
naculum , as  well  as  the  testicle,  is  behind  the  peritoneum; 
and  the  peritoneum  adheres  to  each  of  them  more  firmly 
than  it  does  to  any  of  the  surrounding  parts.  It  seems 
that,  by  the  contraction  of  the  Gubernaculum , the  testicle 
is  moved  down  from  its  original  situation  to  the  abdo- 
minal ring,  and  through  the  abdomipal  ring  into  the 
scrotum.  The  peritoneum,  which  adheres  firmly  to  the 
gubernaculum  and  testicle,  and  is  loosely  connected  to 
the  other  parts,  yields  to  this  operation;  and  when  the  tes- 
ticle has  arrived  near  the  abdominal  ring,  a portion  of  the 
peritoneum  is  protruded  a little  way  before  it  into  the 
scrotum;  forming  a cavity  like  the  finger  of  a glove.  The 
testicle  passes  down  behind  this  process  of  the  peritoneum, 
and  is  covered  by  it  as  it  was  in  the  abdomen.  Although 
it  appears  protruded  into  the  cavity,  it  is  exterior  to  it, 
and  behind  it;  and  the  vessels,  See.  which  belong  to  the 
testicle  are  also  exterior  to  it. 

The  cavity  formed  in  the  scrotum,  by  this  process  of 
the  peritoneum,  necessarily  communicates  with  the  cavity 
of  the  abdomen  at  its  formation;  but  very  soon  after  the 
testicle  has  descended  into  the  scrotum,  the  upper  part  of 


Umbilical  Vessels. 


211 


this  cavity  is  closed  up,  while  the  lower  part  of  the  pro- 
cess continues  unchanged,  and  constitutes  the  Tunica 
Vaginalis  Testis.  In  some  instances  the  upper  part  of  this 
process  does  not  close  up,  and  the  communication  with 
the  cavity  of  the  abdomen  continues.  The  descent  of  the 
intestine  into  the  cavity  thus  circumstanced,  constitutes 
that  species  of  hernia  which  is  denominated  Congenital .* 

The  most  important  peculiarities  in  the  abdomen  of 
the  foetus  are  those  connected  with  the  circulation  of  the 
blood. 

The  internal  iliac  or  hypogastric  arteries  are  larger  than 
the  external  iliacs.  Their  main  trunks  are  continued  on 
each  side  of  the  bladder  to  its  fundus;  and  proceed  from 
it,  with  the  ligament,  to  the  umbilicus;  when  they  pass 
out  of  the  abdomen  to  go  along  the  umbilical  cord  to  the 
placenta.  These  arteries  are  now  denominated  the  Umbili- 
cal, and  are  very  considerable  in  size.  After  birth,  as 
there  is  no  circulation  in  them,  they  soon  begin  to  change: 
the  cavity  of  them  is  gradually  obliterated,  and  they  are 
converted  into  ligaments.  They  are  exterior  to  the  peri- 
toneum, and  contained  in  a duplicature  of  it. 

A vein  also  called  the  Umbilical , which  is  much  larger 

* These  interesting  circumstances  respecting  the  original  situa- 
tion of  the  testicle,  and  its  descent  into  the  scrotum,  were  disco- 
vered and  elucidated  by  Haller,  Hunter,  Pott,  Camper,  and  several 
other  very  respectable  anatomists  and  surgeons.  There  is  however 
a difference  of  opinion,  between  some  of  them,  as  to  the  time  when 
the  testicle  leaves  the  abdomen.  Haller  thought  the  testicles  were 
seldom  in  the  scrotum  at  birth.  Hunter  and  Camper  found  them  so 
generally. 

It  has  been  suggested  that  there  are  some  national  peculiarities  in 
this  respect;  that  amongst  the  Hungarians,  for  example,  the  testi- 
cles often  remain  above  the  abdominal  ring  until  near  the  age  of 
puberty. 

The  student  will  find  an  interesting  description  of  the  situation  of 
the  testis,  and  its  descent,  in  the  foetus,  in  the  lC  Observations  on 
certain  parts  of  the  Animal  Economy,”  by  John  Hunter. 


£12 


Ductus  Venosus . 


in  diameter  than  both  of  the  arteries,  returns  from  the 
placenta  along  the  cord,  and  enters  the  cavity  of  the  ab* 
domen  at  the  umbilicus.  It  proceeds  thence,  exterior  to 
the  peritoneum,  but  in  a duplicature  of  it  called  the  Fal- 
ciform Ligament , to  the  liver,  and  enters  that  viscus  at 
the  great  fissure;  along  which  it  passes  to  the  left  branch 
of  the  sinus  of  the  vena  portarum,  into  which  it  opens  and 
discharges  the  blood  which  flow's  through  it  from  the 
placenta.  It  opens  oh  the  anterior  side  of  the  branch  of  the 
vena  portarum,  and  from  the  posterior  side  of  the  branch, 
opposite  to  this  opening,  proceeds  a duct  or  canal,  which 
opens  into  the  left  hepatic  vein  near  its  junction  with  the 
vena  cava.  This  communicating  vessel  is  called  the  Duc- 
tus, or  Canalis  Venosus;  to  distinguish  it  from  the  duct 
which  passes  from  the  pulmonary  artery  to  the  aorta,  and 
is  calltd  Ductus , or  Canalis  Arteriosus.  This  venous  duct 
carries  some  of  the  blood  of  the  umbilical  vein  directly  to 
the  vena  cava;  but  it  is  much  smaller  than  the  umbilical 
vein,  and  of  course  a considerable  quantity  of  the  blood 
which  passes  through  the  umbilical  vein  must  pass  through 
the  liver,  by  the  vena  portarum,  before  it  can  enter  the 
Cava. 

In  some  foetal  subjects,  if  a probe  of  sufficient  length  be 
introduced  within  the  umbilical  vein  and  pushed  forwards, 
it  will  pass  to  the  heart  without  much  difficulty  or  oppo- 
sition, as  if  it  proceeded  along  one  continued  tube,  al- 
though it  really  passes  from  the  umbilical  vein  across  the 
branch  of  the  vena  portarum,  and  then  through  the  ductus 
venosus,  and  through  a portion  of  the  left  hepatic  vein, 
into  the  inferior  vena  cava. 

If  the  umbilical  vein  be  injected  w'ith  a composition, 
which  will  be  firm  when  cool,  it  appears  to  terminate  in  a 
rounded  end,  which  is  situated  in  the  transverse  fissure 
of  the  liver:  the  sinus  of  the  vena  portarum,  into  which 
this  vein  enters,  appears  like  two  branches  going  off, 
one  from  each  side  of  it,  and  the  ductus  venosus  like 


Object  of  the  Circulation  in  the  Placenta.  21$ 

a branch  continuing  in  the  direction  of  the  main  trunk 
of  the  umbilical  vein. 

The  umbilical  vein,  in  its  progress  through  the  fissure 
«of  the  liver,  before  it  arrives  at  the  sinus  of  the  vena  por- 
tarum,  sends  off  a considerable  number  of  branches  to 
each  of  the  lobes  of  that  organ,  but  more  to  the  left  than 
to  the  right  lobe. 

After  birth,  when  blood  ceases  to  flow  through  the  um- 
bilical vein,  it  is  gradually  converted  into  a ligament;  and 
the  venous  duct  is  also  converted  into  a ligament  in  the 
same  manner.  The  vena  portarum,  which  before  appeared 
very  small,  when  compared  with  the  umbilical  vein,  now 
brings  all  the  blood  which  fills  its  great  sinus,  and  increases 
considerably  in  size. 

It  has  been  ascertained  by  anatomical  investigation, 
that  the  umbilical  arteries  above  mentioned,  after  ramify- 
ing minutely  in  the  placenta,  communicate  with  the  mi- 
nute branches  of  the  umbilical  vein;  and  it  is  probable  that 
the  whole  blood  carried  to  the  placenta  by  these  arteries, 
returns  by  the  umbilical  vein  to  the  foetus. 

It  is  clearly  proved  by  the  effects  of  pressure  on  the 
umbilical  cord,  in  cases  of  delivery  by  the  feet,  as  well  as 
by  other  similar  circumstances,  that  this  circulation  ctvi- 
not  be  suspended  for  any  length  of  time  without  destroy- 
ing the  life  of  the  foetus.  From  these  circumstances,  and 
from  the  florid  colour  which  the  blood  acquires  by  circu- 
lating in  the  placenta,  it  seems  probable  that  the  object  of 
the  circulation  through  that  organ  is  somewhat  analogous 
to  the  object  of  the  pulmonary  circulation  through  the 
lungs  of  adults.  * 

* During  the  first  four  months  of  pregnancy  a very  small  vesicle, 
which  does  not  exceed  the  size  of  a pea,  is  found  between  the  chorion 
and  the  amnios,  near  the  insertion  of  the  umbilical  cord  into  the  pla- 
centa. It  is  connected  to  the  foetus  by  an  artery  and  a vein,  which 
pass  from  the  abdomen  through  the  umbilicus,  and  proceeding 
along  the  cord  to  the  placenta,  continue  from  it  to  the  vesicle.  The 


214  Object  of  the  Circulation  in  the  Placenta. 

artery  arises  from  the  mesenteric,  and  the  vein  is  united  to  the  me- 
senteric branch  of  the  vena  portarum.  It  is  probable  that  these  ves- 
sels commonly  exist  no  longer  than  the  vesicle,  viz.  about  four 
months;  but  they  have  been  seen  by  Haller  and  Chaussier  at  the 
termination  of  pregnancy.  They  are  called  Omfihalo  Mesenteric 
vessels.  The  vesicle  is  denominated  the  Umbilical  Vesicle. 

This  inexplicable  structure  is  delineated  in  Hunter’s  Anatomy 
of  the  Gravid  Uterus,  plate  xxxiii.  figures  v.  and  vi.;  in  the  Aca- 
demical Annotations  of  Albinus,  first  book,  plate  i.  figure  xii.j 
and  also  in  the  leones  Embryonum  Humanorum  of  Soemmering, 
figure  ii. 


SYSTEM  OF  ANATOMY. 


PART  IX. 


OP  THE  BLOODVESSELS. 

The  Bloodvessels  are  flexible  tubes,  of  a peculiar 
texture,  through  which  blood  passes  from  the  heart  to 
the  different  parts  of  the  body,  and  returns  again  from 
these  parts  to  the  heart.  They  are  to  be  found,  in  varying 
proportions,  in  almost  every  part  of  the  body,  and  seem 
to  enter  into  its  texture. 

The  tubes,  which  carry  blood  from  the  heart,  are  more 
substantial  and  more  elastic  than  those  through  which  it 
returns  to  the  heart.  They  are  generally  found  empty 
after  death;  and,  therefore,  were  called  Arteries  by  the 
ancient  anatomists,  who  supposed  that  they  carried  air, 
and  not  blood. 

The  tubes  which  return  the  blood  to  the  heart  are 
denominated  Veins.  They  are  less  substantial  and  less 
elastic  than  arteries,  and  are  generally  full  of  blood  in  the 
dead  subject. 

There  are  two  great  arteries,  from  which  all  the  other 
arterial  vessels  of  the  body  are  derived.  They  are  very 
justly  compared  to  the  trunks  of  trees,  and  the  smaller 
vessels  to  their  branches.  One  cr  these  great  arteries, 


216  The  Bloodvessels  in  general. 

called  the  Aorta , carries  blood  to  every  part  of  the  body. 
The  other  great  vessel,  called  the  Pulmonary  Artery, 
carries  blood  exclusively  to  the  lungs. 

The  veins  which  correspond  to  the  branches  of  the 
Aorta , unite  to  each  other,  so  as  to  form  two  great  trunks 
that  proceed  to  the  heart.  One  of  these  trunks,  coming 
from  the  superior  parts  of  the  body,  is  called  the  Superior , 
or  Descending  Vena  Cava.  The  other,  which  comes  from 
the  lower  parts  of  the  body,  is  called  the  Inferior,  or 
Ascending  Vena  Cava. 

The  veins  which  correspond  with  the  branches  of  the 
Pulmonary  Artery , and  return  to  the  heart  the  blood  of 
the  lungs,  are  four  in  number:  two  of  them  proceeding 
from  each  lung.  They  are  called  Pulmonary  Veins. 

In  many  of  the  veins  there  are  valves,  which  prevent 
the  blood  they  contain  from  moving  towards  the  surface 
and  extremities  of  the  body,  but  allow  it  to  pass  towards 
the  heart  without  impediment. 

From  the  construction  of  the  cavities  of  the  heart,  and 
the  position  of  the  valves  which  are  in  them;  as  well  as  the 
situation  of  the  valves  at  the  commencement  of  the  great 
arteries , and  the  above  mentioned  valves  of  the  veins,  it  is 
evident,  that  when  the  blood  circulates,  it  must  move  from 
the  heart,  through  the  aorta  and  its  branches,  to  the  differ- 
ent parts  of  the  body,  and  return  from  these  parts  through 
the  venae  cavas  to  the  heart;  that,  when  deposited  in  the 
heart  by  the  venae  cavae,  it  must  proceed  through  the  pul- 
monary artery  to  the  lungs,  and  return  from  the  lungs 
through  the  pulmonary  veins  to  the  heart,  in  order  to 
pass  again  from  that  organ  into  the  aorta. 

It  is  also  certain,  that  the  blood  is  forced  from  the 
heart  into  the  arteries,  by  the  contraction  of  the  muscular 
fibres  of  which  the  heart  is  composed;  and  that  the  blood- 
vessels likewise  perform  a part  in  the  circulation,  they 
propelling  the  blood  which  is  thus  thrown  into  them:  but 
their  action  appears  to  depend  upon  causes  of  a complex 
nature. 


CHAPTER  I. 


OF  THE  GENERAL  STRUCTURE  AND  ARRANGEMENT  OF  THE 
BLOODVESSELS. 

SECTION  I. 

Of  the  Arteries. 

XHE  arteries  are  so  much  concerned  in  the  important 
function  of  the  circulation  of  the  blood,  that  every  cir- 
cumstance connected  with  them  is  very  interesting. 

They  are  composed  of  coats  or  tunics,  which  are  very 
elastic  and  strong,  and  which  arc  also  very  thick.  In  con- 
sequence of  the  firmness  of  their  coats,  they  continue 
open,  after  their  contents  are  discharged,  like  hard  tubes. 
They  submit  to  great  dilatation,  and  elongation,  when 
fluids  are  forced  into  them,  and  return  to  their  former 
dimensions  when  the  distending  cause  is  withdrawn.  This 
elasticity  is  particularly  subservient  to  the  circulation  of 
the  blood.  It  admits  the  artery  to  distend  readily,  and 
receive  the  blood  which  is  thrown  into  it  by  the  contrac- 
tion of  the  heart.  It  also  produces  the  contraction  of  the 
artery;  which  takes  place  as  soon  as  the  action  of  the 
heart  ceases;  and  this  contraction  of  the  artery  necessarily 
forces  the  blood  forward,  as  the  valves  at  its  orifice  pre- 
vent it  from  returning  to  the  heart. 

The  motion  of  the  artery,  which  is  so  easily  perceived 
by  the  touch,  and  in  many  instances  also  by  the  eye,  is 
completely  explained  by  the  discharge  of  blood  into  the 
artery  from  the  heart,  and  by  the  elasticity  of  the  vessel, 
by  which  it  reacts  upon  the  blood.  In  some  cases  it  is  not 
Vol,  II.  2 E 


218 


Structure  of  the  Arteries. 

simply  the  diameter  of  the  artery  which  is  enlarged,  but 
a portion  of  the  vessel  is  elongated;  and  this  elongation, 
by  producing  a curvature  of  it,  renders  its  motion  more 
visible. 

In  the  aorta,  and  probably  in  its  large  branches,  Elasti- 
city seems  to  be  the  principal  cause  of  the  continuance  of 
the  motion  which  is  originally  given  to  the  blood  by  the 
heart.  But  there  are  many  circumstances  connected  with 
the  smaller  vessels,  which  evince  that  they  exert  a power 
which  is  very  different  indeed  from  elasticity.  Thus  the 
application  of  local  stimulants  or  rubefacients,  and  of 
heat,  is  followed  by  an  increase  of  motion  in  the  arteries 
of  the  parts  to  which  they  are  applied.  Neither  of  these 
causes  could  produce  their  effect  by  the  influence  of 
elasticity:  but  the  effect  of  these  and  other  similar 
causes  is  uniformly  produced;  and  a power  of  inde- 
pendent motion,  or  Irritability , is  thus  proved  to  exist 
in  these  vessels,  and  seems  essentially  necessary  to  the 
circulation  of  the  blood. 

The  Structure  of  the  Arteries 

Is,  therefore,  a subject  of  importance,  and  has  reeeived 
a considerable  degree  of  attention  from  anatomists. 

They  are  composed  of  a dense  elastic  substance,  of 
a whitish  colour.  Their  external  surface  is  rough,  and 
intimately  connected  with  the  cellular  membrane,  which 
every  where  surrounds  it  in  varying  quantities.  Inter- 
nally, they  are  lined  with  a thin  membrane,  which  is  very 
smooth  and  flexible,  and  is  also  very  elastic.  The  sub- 
stance which  composes  the  artery,  and  is  situated  between 
the  cel1  ar  investment  and  the  internal  membrane,  con- 
sists of  fibres,  which  are  nearly,  though  not  completely, 
circular,  but  so  arranged  as  to  constitute  a cylinder.  These 
fibres  may  be  separated  from  each  other  so  as  to  form 
laminze,  which  have  been  considered  as  different  coats  of 


219 


Structure  of  the  Arteries. 

the  arteries;  but  there  is  no  arrangement  of  them  which 
composes  regular  distinct  strata.  The  coats  of  arteries 
may,  therefore,  be  separated  into  a greater  or  smaller 
number  of  laminae,  according  to  the  thickness  of  these 
lamina;. 

The  fibres  which  compose  these  laminae  appear  to  be 
united  to  each  other  in  a way  which  readily  allows  of 
their  separation,  at  the  same  time  that  they  form  a firm 
texture.  Although  arteries  thus  appear  essentially  different 
from  muscles  in  their  hardness  and  their  elasticity,  as 
well  as  in  their  general  texture,  they  are  considered,  by 
a great  majority  of  anatomists,  as  partaking  more  or  less 
of  a muscular  structure. 

In  the  human  subject  their  structure  is  very  difficult  of 
demonstration,  and  great  differences  exist  in  the  accounts 
which  are  given  of  it,  even  by  anatomists,  who  agree  in  the 
general  sentiment  that  the  arteries  are  muscular. 

Thus  Haller  believed  that  muscular  fibres  were  most 
abundant  in  the  large  arteries,  while  J.  Hunter  thought 
the  reverse. 

Hunter  appears  to  have  investigated  this  subject  with 
great  attention,  and  supposed  the  muscular  substance,  in 
the  composition  of  arteries,  to  be  interior,  and  the  elastic 
matter  exterior;  that  in  large  arteries  this  muscular  sub- 
stance is  very  small  in  quantity,  and  gradually  increases 
in  proportion  as  the  artery  diminishes  in  size.  He  however 
observes,  that  he  never  could  discover  the  direction  of  the 
muscular  fibres .* 

When  the  great  talents  of  Mr.  Hunter,  as  an  anatomist, 
are  considered,  this  circumstance  cannot  fail  to  excite  a 
belief  that  the  existence  of  these  fibres  is  not  certain:  and 
if  to  this  be  added  the  fact,  that  even  the  red  coloured 
substance  of  the  arteries  is  elastic,  and  in  that  respect  dif- 
ferent from  muscular  substance,  the  reasons  for  doubt- 
ing must  be  increased. 

* Treatise  on  the  Blood,  &c.  Vol.  I.  p.  1 1 J.  Bradford’s  edition. 


220  Question  respecting  the  muscularity  of  Arteries. 

Bichat  appears  to  have  entertained  very  strong  doubts 
on  the  subject;  but  he  stands  almost  alone;  for  a large 
number  both  of  the  preceding  and  cotemporary  anato- 
mists, seem  to  have  adopted  the  sentiment,  that  the  arte- 
ries have  a muscular  structure. 

The  student  of  anatomy  can  very  easily  examine  this 
subject  himself,  by  separating  the  coats  of  arteries  into  dif- 
ferent lamina;  and  by  viewing  the  edges  of  the  transverse 
and  longitudinal  sections  of  those  vessels.  While  thus 
engaged  with  this  question,  he  will  read  with  great  advan- 
tage what  has  been  written  upon  it  by  Mr.  Hunter,  in  his 
Treatise  on  the  Blood,  See.  See  chapter  second,  section  3. 
Bichat  ought  also  to  be  read  upon  this  subject,  which  he 
has  discussed  in  his  Anatomie  Generale — System  Vascu- 
laire  a Sang  Rouge , article  Troisieme,  See.  and  also  in  his 
Traite  des  Membranes , article  Sixieme. 

The  belief  of  the  irritability  of  arteries  does  not,  how- 
ever, rest  upon  the  appearance  of  theii  hbres. 

1.  It  is  asserted  by  very  respectable  authors,*  that  they 
have  been  made  to  contract  by  the  application  of  mecha- 
nical and  of  chemical  irritation,  and  also  of  the  electric 
and  galvanic  power. 

2.  A partial  or  local  action  of  arteries  is  often  pro- 
duced by  the  local  application  of  heat  and  rubefacients,  as 
has  been  already  observed. 

3.  Arterial  action  is  often  suspended  in  a particular 
part  by  the  application  of  cold.  It  has  also  been  observed 
that  the  arteries  have  for  a short  time  ceased  to  pulsate 
in  cases  of  extreme  contusion  and  laceration  of  the 
limbs. t 

* See  Soemmering  on  the  structure  of  the  Human  Body,  Vol.  IV”. 
German  edition.  Dr.  Jones  on  the  Process  employed  by  nature  for 
suppressing  Haemorrhage,  &c. 

t This  local  suspension  of  arterial  motion  by  cold,  kc.,  applied 
locally,  is  very  difficult  to  explain;  as  the  action  of  the  heart  and  the 
elasticity  of  the  arteries  appear  sufficient  to  account  for  the  pulsation 
of  the  large  arteries. 


Proofs  of  the  Irritability  of  the  Arteries.  221 

4.  When  arteries  are  divided  transversely  in  living 
animals,  they  often  contract  so  as  to  close  completely  the 
orifice  made  by  the  division. 

5.  In  a horse  bled  to  death,  it  was  ascertained  by  Mr. 
Hunter,  that  the  transverse  diameter  of  the  arteries 
was  diminished  to  a degree  that  could  not  be  explained 
by  their  elasticity.  He  also  found  that,  after  death,  the 
arteries,  especially  those  of  the  smaller  size,  are  generally 
in  a state  of  contraction,  which  is  greater  than  can  be 
explained  by  their  elasticity:  for  if  they  are  distended 
mechanically,  they  do  not  contract  again  to  their  former 
size,  but  continue  of  a larger  diameter  than  they  were 
before  the  distention;  although  their  elasticity  may  act  so 
as  to  restore  a very  considerable  degree  of  the  contraction 
observed  at  death. 

The  contraction,  which  is  thus  done  away  by  disten- 
tion, Mr.  Hunter  supposed  to  have  been  produced  by 
muscular  fibres:  for,  if  it  had  been  dependent  on  elastici- 
ty, it  must  have  reappeared  when  the  distending  power 
was  withdrawn. 

It  therefore  seems  certain,  that  the  arteries  have  a 
power  of  contraction  different  from  that  which  depends 
upon  elasticity:  but  whether  this  depends  upon  muscular 
fibres  superadded  to  them,  or  upon  an  irritable  quality 
in  the  ordinary  elastic  fibres  of  bloodvessels,  is  a question 
which  is  not  perhaps  completely  decided. 

The  motion  of  the  blood  in  the  arteries  appears  to 
depend, 

1st,  Upon  the  impulse  given  to  it  by  the  action  of 
the  heart. 

2dly,  Upon  the  elasticity  of  the  arteries,  in  consequence 
of  which  they  first  give  way  to  the  blood  impelled  into 
them,  and  then  react  upon  it;  and 

3dly,  Upon  the  power  of  contraction  in  the  arteries,  or 
their  irritability. 

In  the  larger  arteries  the  blood  seems  to  move  as  it 


222  General  Observations  on  the  Arteries * 

Would  through  an  inanimate  elastic  tube,  in  consequence 
of  the  impulse  given  by  the  heart,  and  kept  up  by  the 
arteries  themselves.  In  the  smaller  vessels  it  seems  pro- 
bable that  the  motion  of  the  blood  depends  in  a consi- 
derable degree  upon  the  contraction  Which  arises  from 
their  irritability. 

The  obvious  effect  of  the  elasticity  of  the  arteries  is  to 
resist  distention  and  elongation,  and  to  contract  the  artery 
to  its  natural  state,  when  the  distending  or  elongating 
cause  ceases  to  act.  But  it  must  also  resist  the  contraction 
induced  by  the  muscular  fibres,  and  restore  the  artery  to 
its  natural  size  when  the  muscular  fibres  cease  to  act  after 
contracting  it,  as  has  been  observed  by  Mr.  Hunter. 

It  seems  probable  that  all  the  fibres  of  which  the  artery 
consists  are  nearly  but  not  completely  circular;  for  it 
is  not  certain  that  there  are  any  longitudinal  fibres  in  the 
structure  of  an  artery. 

The  internal  coat  of  these  vessels  is  very  smooth,  but 
extremely  dense  and  firm;  and  seems  to  be  rendered 
moist  and  flexible  by  an  exudation  on  its  surface.  It 
adheres  very  closely  to  the  contiguous  fibres  of  the  coat 
exterior  to  it,  but  may  be  very  readily  peeled  off  from 
them.  It  is  of  a whitish  colour,  and,  like  the  fibrous 
structure  of  the  artery,  is  very  elastic.  Like  that  sub- 
stance also  it  is  easily  torn  or  broken,  and,  when  ligatures 
have  been  applied  to  arteries,  it  has  been  often  observed 
that  the  fibrous  structure  and  the  internal  coat  have  been 
separated,  while  this  external  cellular  coat  has  remained 
entire. 

The  arteries  are  supplied  with  their  proper  blood- 
vessels and  lymphatics.  It  is  to  be  observed,  that  the 
bloodvessels  are  not  derived  from  the  artery  on  which 
they  run,  but  from  the  contiguous  vessels. 

These  vessels  have  nerves  also,  which  are  rather  small 
in  size,  when  compared  with  those  which  go  to  other 
parts. 


General  Observations  on  the  Arteries.  223 

Arteries  appear  to  have  a cylindrical  form,  for  no  di- 
minution of  diameter  is  observable  in  those  portions  of 
them  which  send  off  no  ramifications. 

When  an  artery  ramifies,  the  area  of  the  different 
branches  exceeds  considerably  that  of  the  main  trunk. 
Upon  this  principle  the  aorta  and  its  branches  have 
been  compared  to  a cone,  the  basis  of  which  is  formed 
by  the  branches,  and  the  apex  of  the  trunk. 

The  transverse  section  of  an  artery  is  circular. 

There  are  no  valves  in  the  arteries,  except  those  of  the 
orifices  of  the  aorta  and  the  pulmonary  artery,  at  the  heart. 
The  valves  of  the  pulmonary  artery  have  been  described 
in  the  53d  page  of  this  volume,  and  those  of  the  aorta 
have  an  exact  resemblance  to  them,  but  are  rather 
larger. 

The  course  of  the  arteries  throughout  the  body  is  ob- 
viously calculated  to  prevent  their  exposure  to  pressure, 
or  to  great  extension  from  the  flexure  of  the  articulations 
by  which  they  pass.  With  this  view  they  sometimes  pro- 
ceed in  a winding  direction;  and  when  they  pass  over 
parts  which  are  subject  to  great  distention  or  enlarge- 
ment, as  the  cheeks,  they  often  meander;  and,  therefore, 
their  length  may  be  increased  by  straightening,  without 
stretching  them. 

Their  course  appears  sometimes  to  have  been  calcula- 
ted to  lessen  the  force  of  the  blood,  as  is  the  case  with 
the  Internal  Carotid  and  the  Vertebral  arteries. 

In  the  trunk  of  the  body  the  branches  of  arteries  gen- 
erally form  obtuse  angles  with  the  trunks  from  which 
they  proceed.  In  the  limbs  these  angles  are  acute. 

The  communication  of  arteries  with  each  other  is 
termed  Anastomosis.  In  some  instances,  two  branches 
which  proceed  in  a course  nearly  similar,  unite  with 
an  acute  angle,  and  form  one  common  trunk.  Some- 
times, a transverse  branch  runs  from  one  to  the  other, 
so  as  to  form  a right  angle  with  each.  In  other  cases, 


224  General  Observations  on  the  Veins. 

the  two  anastamosing  branches  form  an  arch,  or  portion 
of  a circle,  from  which  many  branches  go  off. 

By  successive  ramifications,  arteries  gradually  dimi- 
nish in  size,  until  they  are  finally  extremely  small. 

The  smallest  arteries  do  not  carry  red  blood,  their 
diameters  being  smaller  than  those  of  the  red  particles 
of  that  fluid:  the  serous  or  aqueous  part  of  the  blood  can, 
therefore,  only  pass  through  them. 

Many  of  the  arteries  which  carry  red  blood,  and  of  the 
last  mentioned  serous  arteries  terminate  in  veins,  which 
are,  in  some  respects,  a continuation  of  the  tube  reflected 
backwards. 

They  likewise  terminate  in  exhalent  vessels,  which  open 
upon  the  external  surface,  and  upon  the  various  internal 
surfaces  of  the  body.  The  secretory  vessels  of  glands  are 
likewise  the  termination  of  many  atteries. 


SECTION  II. 

Of  the  Veins. 

THESE  tubes,  which  return  to  the  heart  the  blood 
carried  from  it  by  the  arteries,  are  more  numerous  than 
the  arteries,  and  often  are  larger  in  diameter. 

They  generally  accompany  the  arteries,  and  very  often 
two  veins  are  found  with  one  artery. 

In  addition  to  these  last  mentioned  veins,  which  may 
be  called  deep-seated , there  are  many  subcutaneous  veins 
which  appear  on  almost  every  part  of  the  surface  of  the 
body. 

The  capacity  of  all  the  veins  is  therefore  much  greater 
than  that  of  all  the  arteries. 

Those  subcutaneous  veins,  which  are  of  considerable 


225 


Coats  of  V eins. 

size,  communicate  very  freely  with  each  other,  and  also 
with  the  deep-seated  veins. 

The  trunks  of  the  veins,  in  those  places  where  no 
branches  go  off,  are  generally  cylindrical.  There  are 
however  some  exceptions,  in  which  these  vessels  are  irre- 
gularly dilated,  as  sometimes  happens  in  the  case  of  the 
internal  jugular  vein.  It  is,  however,  not  easy  to  determine 
from  the  appearance  of  veins  injected  after  death,  respect- 
ing their  situation  during  life,  as  their  coats  are  very 
yielding;  and  it  is  very  probable  that  they  are,  therefore, 
preternaturally  dilated  by  the  injection. 

Veins , directly  or  indirectly,  originate  from  the  termi- 
nation of  arteries:  but  they  do  not  pulsate  as  the  arteries 
do,  because  the  impulse  given  to  the  blood  by  the  heart 
is  very  much  diminished  in  consequence  of  the  great 
diminution  of  the  size  of  the  vessels  through  which  the 
blood  has  passed. 

In  some  cases,  however,  when  blood  flows  from  an 
opened  vein;  the  extent  of  its  projection  is  alternately 
increased  and  diminished,  in  quick  succession,  as  if  it  were 
influenced  by  the  pulsation  of  the  heart. 

The  Coats  of  Veins  differ  considerably  from  those  of 
Arteries , — for  they  are  thinner,  and  so  much  less  firm , 
that  veins,  unlike  arteries,  collapse  when  they  are  empty. 

They  consist  of  a dense  elastic  substance,  the  fibres  of 
which  are  much  less  distinct  than  those  of  arteries,  but 
some  of  them  are  to  be  seen  in  a longitudinal  direction. 
These  fibres  can  be  made  to  contract  by  loc\J  irritation ; 
for  if  a vein  be  laid  bare  in  a living  animal,  and  then 
punctured,  it  will  often  contract  so  as  to  diminish  its 
diameter  very  considerably,  although  no  blood  shall  have 
escaped  from  the  punctures. 

Nextto  the  elastic  substance  is  the  internal  coat,  which 
is  smooth  and  polished.  It  is  separated  from  the  substance 
exterior  to  it  with  difficulty,  although  it  may  be  taken  from 
it  very  easily  in  the  vena  cava. 

Vol.  II.  2 F 


226 


Colour  of  the  Blood  in  the  Veins. 

This  internal  coat  is  more  distendible  than  the  internal 
coat  of  arteries,  and  is  not,  like  the  latter,  disposed  to  os- 
sification. It  is  frequently  so  arranged  as  to  form  valves, 
which  are  plaits  or  folds,  of  a semilunar  form,  that  project 
from  the  surfaces  into  the  cavities  of  these  vessels. 

Two  of  these  valves  are  generally  placed  opposite  to 
each  other;  and,  when  raised  up,  they  form  a septum 
in  the  cylindrical  cavity  of  the  vessel.  The  septum,  thus 
composed,  is  concave  towards  the  heart. 

The  valves  have  a great  effect  in  preventing  the  contents 
of  the  veins  from  moving  in  a retrograde  course:  they, 
therefore,  necessarily  modify  the  effects  of  lateral  pressure, 
in  such  a manner,  that  it  propels  the  blood  forward,  or 
to  the  heart. 

These  valves  are  generally  found  in  the  veins  of  the 
muscular  parts  of  the  body,  especially  in  those  of  the 
extremities.  They  are  not  found  in  those  veins  which  are 
in  the  cavities  of  the  body,  nor  in  the  internal  jugulars. — 
They  are  placed  at  unequal  distances  from  each  other. 

The  coats  of  the  veins  are  somewhat  transparent;  and, 
therefore,  those  veins  which  are  subcutaneous  have  a 
bluish  aspect,  which  is  derived  from  the  colour  of  the 
blood  they  contain. 

The  colour  of  the  blood  in  the  Veins  is  different  from 
that  in  the  arteries,  being  of  a darker  red. 

The  situation  and  arrangement  of  the  large  trunks  of 
veins  is  much  alike  in  different  subjects;  but  the  branches, 
especially  those  which  are  subcutaneous,  are  very  variable 
in  their  situations. 


227 


CHAPTER  II. 

A PARTICULAR  ACCOUNT  OF  THE  DISTRIBUTION  OF  THE 
ARTERIES. 

SECTION  I. 

Of  the  AORTA, 

Or  the  Great  Trunk  of  the  Arterial  System. 

When  the  heart  is  in  its  natural  position,  the  right 
ventricle  is  nearly  anterior  to  the  left;  and,  therefore,  the 
AORTA,  where  it  originates  from  the  left  ventricle,  is 
behind  the  pulmonary  artery,  and  covered  by  it.  Its  first 
direction  is  so  oblique  towards  the  right  side  of  the  body, 
that  it  crosses  the  pulmonary  artery  behind,  and  appears 
on  the  right  side  of  it.  It  has  scarcely  assumed  this  posi- 
tion before  its  course  alters,  for  it  then  proceeds  obliquely 
backwards,  and  to  the  left;  so  as  to  form  a large  curve 
or  arch,  which  extends  to  the  left  of  the  spine. 

The  position  of  this  curve  or  arch  is  so  oblique,  with 
respect  to  the  body,  that  the  cord  or  diameter  of  it,  if  it 
were  extended  anteriorly  and  posteriorly,  would  strike  the 
cartilage  of  the  second  or  third  right  rib  about  the  mid- 
dle of  its  length,  and  the  lejt  rib  near  the  head.  In  conse- 
quence of  this  position  of  the  curve,  the  AORTA  crosses 
over  the  right  branch  of  the  pulmonary  artery,  and  the 
left  branch  of  the  windpipe:  and  assumes  a situation,  in 
front,  and  to  the  left  of  the  third  dorsal  vertebra:  from 
this  situation  it  proceeds  downwards;  in  front,  but  rather 
on  the  left  side  of  the  spine,  and  in  contact  with  that  co- 
lumn. 


228  Situation  of  the  Aorta  in  the  Thorax  and  Abdomen. 

The  AORTA,  as  well  as  the  Pulmonary  Artery , for  a 
small  distance  from  the  heart,  is  invested  by  the  peri- 
cardium; and,  when  that  sac  is  opened,  appears  to  be 
contained  in  it. 

After  crossing  the  right  branch  of  the  Pulmonary 
Artery , a ligament  is  inserted  into  it,  which  proceeds 
from  the  main  trunk  of  the  pulmonary  artery  at  its  divi- 
sion: this  ligament  was  the  Canalis  Arteriosus  in  the 
foetus. 

As  the  AORTA  proceeds  down  the  spine,  it  is  situa- 
ted between  the  two  laminae  of  the  mediastinum,  and  in 
contact  with  the  left  lamina,  through  which  it  may  be 
seen.  It  descends  between  the  crura  of  the  diaphragm,  in 
a vacuity  which  is  sufficiently  large  to  admit  of  its  pas- 
sage without  pressure  from  the  surrounding  parts,  and  is 
still  in  contact  with  the  anterior  surface  of  the  spine,  but 
rather  to  the  left  of  the  middle  of  it.  It  continues  this 
course  along  the  spine  until  it  arrives  at  the  cartilaginous 
substance  between  the  fourth  and  fifth  lumbar  vertebrae, 
when  it  divides  into  two  great  branches  of  equal  size, 
which  form  an  acute  angle  with  each  other.  These  are  de- 
nominated the  COMMON,  or  PRIMITIVE  ILIAC 
Arteries. 

From  the  AORTA  in  this  course  are  sent  off  the  ar- 
teries which  are  distributed  to  all  the  parts  of  the  body 
for  their  nourishment  and  animation, 

From  the  curve  proceed  the  great  branches  which  sup- 
ply the  heart,  the  head,  the  upper  extremities,  and  part 
of  the  thorax.  Between  the  curve  and  the  great  primitive 
iliac  arteries,  the  AORTA  sends  off  those  branches  which 
supply  the  viscera  contained  in  the  cavities  of  the  thorax 
and  abdomen,*  and  part  of  the  trunk  of  the  body.  The 
great  ILIAC  branches  of  the  AORTA  are  divided  into 

* It  ought  to  be  observed  here,  that  the  viscera  in  the  lower  part 
of  the  pelvis  receive  some  branches  from  the  internal  iliac  arteries. 


Origin  of  the  Subclavian  and  Carotid  Arteries [.  229 

smaller  arteries,  which  supply  the  whole  of  the  lower 
extremities  and  some  of  the  viscera  of  the  pelvis. 


SECTION  II. 

Of  the  Branches  which  go  off  from  the  arch  of  the 
AORTA. 

THE  proper  arteries  of  the  heart,  denominated  coro- 
nary arteries,  proceed  from  the  AORTA  so  near  to 
the  heart  that  their  orifices  are  covered  by  the  semilunar 
valves,  when  those  valves  are  pressed  against  the  sides  of 
the  artery.  These  arteries  have  been  described  in  the 
account  of  the  heart. — See  p.  57. 

The  arteries  of  the  head  and  of  the  upper  extremities 
proceed  from  the  upper  part  of  the  curve  in  the  following 
manner. 

A large  trunk,  called  ARTERIA  INNOMINATA, 
goes  off  first.  This  is  more  than  sixteen  lines  in  length, 
tvhen  it  divides  into  two  branches:  one  of  which  supplies 
the  right  side  of  the  head,  and  is  denominated  the  RIGHT 
CAROTID:  the  other  proceeds  to  the  right  arm,  and  from 
its  course  under  the  clavicle,  is  called,  at  first,  the  RIGHT 
SUBCLAVIAN.  Almost  in  contact  with  the  first  trunk, 
another  artery  goes  off,  which  proceeds  to  the  left  side  of 
the  head,  and  is  called  the  LEFT  CARO  FID.  Very 
near  to  this,  arises  the  third  artery,  which  proceeds  to 
the  left  arm,  and  is  denominated  the  LEFT  SUBCLA- 
VIAN. From  these  great  branches  originate  the  blood- 
vessels, which  are  spent  upon  the  head  and  neck  and 
the  upper  extremities. 

As  these  arteries  arise  from  the  curve  of  the  AORTA, 
they  are  situated  obliquely  with  respect  to  each  other. 


230  Situation  of  the  Common  Carotid  Arteries. 

*1  he  ARTERIA  INNOMINATA  is  not  only  to  the 
right,  but  it  is  also  anterior  to  the  two  others:  and  the 
LEF  I’  SUBCLAVIAN  is  posterior,  as  well  as  to  the 
left  of  the  LEFT  CAROTID  and  the  ARTERIA  IN- 
NOMINATA. 

THE  CAROTID  ARTERIES. 

The  two  carotid  arteries  above  mentioned  have  been 
denominated  COMMON  CAROTIDS,  to  distinguish 
them  from  their  first  ramifications,  which  are  called  IN- 
TERNAL and  EXTERNAL  CAROTIDS. 

THE  COMMON  CAROTIDS 

Proceed  towards  the  head  on  each  side  of  the  trachea:  at 
first  they  diverge,  but  they  soon  become  nearly  parallel 
to  each  other,  and  continue  so  until  they  have  ascended 
as  high  as  the  upper  edge  of  the  thyroid  cartilage,  when 
they  divide  into  the  INTERNAL  and  EXTERNAL 
CAROTIDS. 

These  arteries  are  at  first  very  near  each  other,  and 
rather  in  front  of  the  trachea;  they  gradually  diverge  and 
pass  backwards  and  outwards  on  the  sides  of  it,  and  of 
the  oesophagus,  until  they  have  arrived  at  the  larynx.  In 
the  lower  part  of  the  neck  they  are  covered  by  the  sterno 
mastoidei,  the  sterno  hyoidei,  and  thyroidei,  as  well  as 
by  the  platysma  myoidei  muscles.  Above,  their  situation 
is  more  superficial;  and  they  are  immediately  under  the 
platysma  myoides. 

On  the  inside,  they  are  very  near  the  trachea  and  la- 
rynx, and  the  oesophagus;  on  the  outside,  and  rather  ante- 
rior to  them,  are  the  internal  jugular  veins;  and  behind, 
on  each  side,  are  two  important  nerves  called  the  inter- 
costal and  the  parvagum.  These  bloodvessels  and  nerves 
are  surrounded  by  absorbent  vessels. 


External  Carotid  Artery.  231 

The  COMMON  CAROTID  ARTERIES  send  off 
no  branches  from  their  origin  to  their  bifurcation;  and 
they  appear  to  preserve  the  same  diameter  throughout 
their  whole  extent.  In  some  few  instances  the  right  caro- 
tid has  been  found  larger  than  the  left.  The  external  and 
internal  branches  into  which  they  divide,  are  nearly  equal 
in  the  adult;  but  it  is  supposed  that  the  internal  is  the  largest 
during  infancy.  The  relative  position  of  these  branches 
is  also  different  at  the  commencement  from  what  it  is 
afterwards.  The  INTERNAL  CAROTID  forms  a curve 
which  projects  outwardly,  so  as  to  be  exterior  to  the 
EXTERNAL  CAROTID,  while  this  last  proceeds  up- 
wards, and  rather  backwards. 

THE  EXTERNAL  CAROTID  ARTERY 

May  be  considered  as  extending  from  its  commence- 
ment, which  is  on  a line  with  the  superior  margin  of  the 
thyroid  cartilage,  to  the  neck  of  the  condyle  of  the  lower 
jaw,  or  near  it. 

At  first  it  is  superficial;  but  as  it  proceeds  upwards  it 
becomes  deep-seated;  and  passing  under  the  digastric  and 
stylo  hyoidei  muscles,  and  the  ninth  pair  of  nerves,  is  co- 
vered by  the  Parotid  Gland.  After  this,  it  again  becomes 
superficial;  for  the  temporal  artery,  which  may  be  regard- 
ed as  the  continuation  of  the  external  carotid,  passes 
over  the  zygomatic  process  of  the  temporal  bone. 

As  the  external  carotid  supplies  with  blood  the  upper 
part  of  the  neck  and  throat,  the  exterior  of  the  head  and 
face,  and  the  inside  of  the  mouth  and  nose;  its  branches 
must  necessarily  be  numerous,  and  must  pass  in  very  va- 
rious directions. 

Thus,  soon  after  its  commencement,  it  sends  off,  in  an 
anterior  direction,  three  large  branches;  viz.  to  the  upper 
part  of  the  neck,  to  the  parts  within  the  lower  jaw,  and  to 
the  cheeks  and  lips.  These  are  denominated,  the  stjpe- 


232  External  Carotid  and  its  Branches. 

rior  thyroid,  the  sublingual,  and  the  facial.  It 
then  sends  off  to  the  back  of  the  head  one  which  is  called 
the  occipital;  and,  as  it  proceeds  upwards  near  the  con- 
dyle of  the  lower  jaw,  another  which  passes  internally,  be- 
hind the  jaw,  to  the  deep-seated  parts  in  that  direction. 
After  this,  it  forms  the  temporal  artery,  which  supplies 
the  forehead  and  central  parts  of  the  cranium.  Besides 
these  larger  branches,  the  external  carotid  sends  off  two 
which  are  smaller;  one  from  near  the  origin  of  the  sublin- 
gual artery,  which  is  spent  principally  upon  the  pharynx 
and  fauces,  and  is  called  the  inferior  pharyngeal: 
and  another,  while  it  is  involved  with  the  parotid  gland, 
which  goes  to  the  ear;  and  is  therefore  called  posterior 
auris. 

These  arteries  are  distributed  in  the  following  manner. 

1.  The  Superior  thyroid  branch 

Comes  off  very  near  the  root  of  the  external  carotid,  and 
sometimes  from  the  common  trunk;  it  runs  obliquely 
downwards  and  forwards,  in  a meandering  course,  to  the 
thyroid  gland,  where  it  is  spent.  During  this  course  it 
sends  off  one  branch  to  the  parts  contiguous  to  the  os 
hyoides;  another  to  the  neighbourhood  of  the  larynx:  and 
a third  branch,  which  may  be  termed  Laryngeal , that 
passes  with  a small  nerve  derived  from  the  laryngeal 
branch  of  the  par  vagum,  either  between  the  os  hyoides 
and  thyroid  cartilage,  or  the  thyroid  and  cricoid  carti- 
lages, to  the  interior  muscles  of  the  larynx;  and  finally 
returns  again  to  terminate  externally. 

While  in  the  thyroid  gland  this  artery  anastomoses 
with  the  inferior  thyroid,  and  also  with  its  fellow  on  the 
opposite  side. 


Branches  of  the  External  Carotid. 


233 


2.  The  lingual,  or  sublingual  branch, 

Goes  off  above  the  last  mentioned  arter}',  and  very  near 
it;  but  in  a very  different  direction,  for  it  runs  upwards 
and  forwards,  to  the  tongue.  In  this  course  it  crosses 
obliquely  the  os  hyoides,  and  is  commonly  within  the 
hyoglossus  muscle.  It  gives  off  branches  to  the  middle 
constrictors  of  the  pharynx,  and  to  the  muscles  contigu- 
ous to  the  tongue.  It  also  sends  off  a branch  which  pene- 
trates to  the  back  of  the  tongue,  which  is  called,  from  its 
situation,  Dorsalis  Lingiue.  At  the  anterior  margin  of  the 
hyoglossus  muscle  it  divides  into  two  branches,  one  of 
which  passes  to  the  sublingual  gland  and  the  adjacent 
parts,  and  is  thence  called  Sublingual ; while  the  other 
branch,  the  Banina,  passes  by  the  side  of  the  genio  glos- 
sus  muscle  to  the  apex  of  the  tongue. 

3.  The  facial  or  external  maxillary, 

Runs  obliquely  upwards  and  forwards  under  the  ninth 
pair  of  nerves,  the  stylo  hyoideus  muscle  and  the  tendon 
of  the  digastric,  across  the  lower  jaw  and  cheek,  towards 
the  inner  corner  of  the  eye,  in  a serpentine  course.  Be- 
fore it  crosses  the  jaw  it  sends  off  several  branches,  viz: 
to  the  pharynx,  the  tonsils,  the  inferior  maxillary  gland 
and  the  parts  contiguous  to  it.  It  also  sends  a branch 
towards  the  chin,  which  passes  between  the  mylo-hyoi- 
deus,  the  anterior  belly  of  the  digastric,  and  the  margin 
of  the  lower  jaw:  and  some  of  its  branches  continue  to 
the  muscles  of  the  under  lip.  This  branch  is  called  the 
Submental. 

This  artery  then  passes  round  the  basis  or  inferior 
edge  of  the  lower  jaw,  very  near  the  anterior  margin  of 
the  masseter  muscle,  and  is  sp  superficial  that  its  pulsa- 
tions can  be  readily  perceived.  After  this  turn,  its  course 
VoL.  II.  2 G 


"34  Branches  of  the  External  Carotid. 

is  obliquely  upwards,  and  forwards.  Near  the  basis  of 
the  jaw  it  sends  off  a branch  to  the  masseter,  which 
anastomoses  with  small  branches  from  the  temporal;  and 
another  which  passes  superficially  to  the  under  lip  and 
contiguous  parts  of  the  cheeks.  This  last  is  called  the 
Inferior  Labial. 

After  the  artery  has  passed  as  high  as  the  teeth  in  the 
lower  jaw,  it  divides  into  two  branches;  which  go,  one 
to  the  under,  and  the  other  to  the  upper  lip:  that  to  the 
upper  lip  is  largest.  These  branches  are  called  Coronary. 

The  Coronary  Artery  of  the  lower  lip  passes  under  the 
muscles  called  Depressor  Anguli  Oris , and  Orbicularis 
Oris , into  the  substance  of  the  lip,  and  anastomoses  with 
its  fellow  of  the  opposite  side. 

The  Coronary  Artery  of  the  upper  lip  passes  under 
the  zygcmaticus  major  and  the  orbicularis,  and  very  near 
the  margin  of  the  upper  lip  internally.  It  also  anasto- 
moses freely  with  its  fellow  on  the  opposite  side.  These 
anastomoses  are  frequently  so  considerable  that  the  ar- 
teries on  one  side  can  be  well  filled  by  injecting  those  of 
the  other.  The  coronary  branches,  as  well  as  the  main 
trunk  of  the  facial  artery,  observe  a serpentine  or  tor- 
tuous course;  in  consequence  of  which  they  admit  of  the 
motions  of  the  cheeks  and  lips,  which  they  would  greatly 
impede  if  they  wrere  straight. 

From  the  upper  coronary  artery  a branch  continues  in 
the  direction  of  the  main  trunk  of  the  facial  artery,  by 
the  side  of  the  nose,  which  extends  upwards,  sending  off 
small  branches  in  its  course,  and  finally  terminates  about 
the  internal  angle  of  the  eye  and  the  forehead. 

4.  The  INFERIOR  PHARYNGEAL 

Is  a very  small  artery;  it  arises  posteriorly  from  the  ex- 
ternal carotid,  opposite  to  the  origin  of  the  sublingual, 
and  passes  upwards  to  the  basis  of  the  cranium.  In  this 


Branches  of  the  External  Carotid.  235 

course  it  sends  several  branches  to  the  pharynx,  and  to 
the  deep  seated  parts  immediately  contiguous. 

It  also  sends  branches  to  the  first  ganglion  of  the  inter- 
costal nerve,  to  the  par  vagum,  and  to  the  lymphatic 
glands  of  the  neck;  and  finally  it  enters  the  cavity  of  the 
cranium  by  the  posterior  foramen  lacerum. 

In  some  cases  it  also  sends  a small  branch  through 
the  anterior  foramen  lacerum. 


5.  The  occipital  artery 

Arises  from  the  posterior  side  of  the  external  carotid, 
nearly  opposite  to  the  facial,  but  sometimes  higher  up; 
it  ascends  obliquely,  and  passes  to  the  back  part  of  the 
cranium,  between  the  transverse  process  of  the  atlas  and 
the  mastoid  process  of  the  temporal  bone. 

In  this  course  it  passes  over  the  internal  jugular  vein 
and  the  eighth  pair  of  nerves,  and  under  the  posterior 
part  of  the  digastric  muscle;  it  lies  very  near  to  the  base 
of  the  mastoid  process,  and  under  the  muscles  -which  are 
inserted  into  it.  After  emerging  from  these  muscles,  it 
runs  superficially  upon  the  occiput,  dividing  into  branches 
which  extend  to  those  of  the  temporal  artery. 

The  occipital  artery  sends  off  branches  to  the 
muscles  which  are  contiguous  to  it,  and  to  the  glands  of 
the  neck. 

It  also  gives  off  the  following  branches:  One  called 
the  Meningeal , which  passes  through  the  posterior  fora- 
men lacerum  to  the  under  and  back  part  of  the  dura 
mater:  one  to  the  exterior  parts  of  the  ear:  another  tvhich 
passes  downwards,  and  is  spent  upon  the  complexus, 
trachelo  mastoideus,  and  other  muscles  of  the  neck:  and 
several  smaller  arteries. 

The  artery  next  to  be  described,  is  sometimes  sent  off 
by  the  occipital  artery. 


236 


Branches  of  the  External  Carotid. 


6.  The  POSTERIOR  AURICULAR,  Or  STYLO  MASTOID 
ARTERY, 

When  it  arises  from  the  external  carotid,  comes  off  pos- 
teriorly from  the  artery,  where  it  is  involved  with  the 
parotid  gland,  and  passes  backwards  between  the  meatus 
auditorius  externus  and  the  mastoid  process.  It  then  as- 
cends, in  a curved  direction,  and  terminates  behind  the 
ear. 

In  this  course  it  sends  off  small  branches  to  the  paro- 
tid gland,  and  to  the  digastric  and  sterno  mastoid  muscles. 
Sometimes  a distinct  branch,  which  is  particularly  visi- 
ble in  children,  passes  through  an  aperture  in  the  meatus 
auditorius  externus,  and  is  spent  on  its  internal  surface. 

It  also  sends  off  a branch  which  enters  into  the  Stylo 
Mastoid  Foramen , and  supplies  small  vessels  to  the  mem- 
brana  tympani  and  the  lining  membrane  of  the  cavity  of 
the  tympanum;  to  the  mastoid  cells;  to  the  muscle  of  the 
stapes,  and  to  the  external  semicircular  canal.  One  of 
these  vessels  anastomoses,  in  the  upper  and  posterior  part 
of  the  cavity  of  the  tympanum,  with  a small  twig  derived 
from  the  artery  of  the  dura  mater.  When  it  has  arrived 
behind  the  ear,  the  Posterior  Auricular  Artery  termi- 
nates upon  the  external  ear  and  the  parts  contiguous  to  it. 

7.  The  INTERNAL  MAXILLARY  ARTERY* 

Arises  from  the  external  carotid  under  the  parotid  gland, 
at  a little  distance  below  the  neck  of  the  condyloid  pro- 

“ The  general  situation  of  this  artery,  and  the  distribution  of  se- 
veral of  its  most  important  branches,  cannot  be  understood  without 
a knowledge  of  the  bones  through  which  they  pass.  The  student  of 
surgery  will  therefore  derive  benefit  from  a re-examination  of  these 
bpnes,  and  of  the  zygomatic  fossa,  &c.  when  he  studies  this  artery. 
'See  Vol.  J.  page  61.) — -He  ought  to  be  well  acquainted  with  this 


237 


The  Internal  Maxillary  Artery. 

cess  of  the  lower  jaw,  and  extends  to  the  bottom  of  the 
zygomatic  fossa;  varying  its  direction  in  its  course.  It 
is  rather  larger  than  the  temporal. 

a.  It  first  sends  off  one  or  two  small  branches  to  the 
ear , and  a twig  which  penetrates  into  the  cavity  of  the 
tympanum  by  the  glenoid  fissure. 

b.  It  also  sends  off  a small  artery  called  the  Lesser 
M&ningeal , which  passes  upwards,  and  after  giving 
branches  to  the  external  pterygoid  and  the  muscles  of 
the  palate,  passes  through  the  foramen  ovale,  and  is 
spent  upon  the  dura  mater  about  the  sella  turcica. 

c.  It  then  sends  off  one  of  its  largest  branches,  the 
' .Great  or  Middle  Artery  of  the  Dura  Mater,  which  passes 

in  a straight  direction  to  the  foramen  spinale,  by  which 
it  enters  into  the  cavity  of  the  cranium. 

This  artery  ramifies  largely  on  the  dura  mater,  and 
makes  those  arborescent  impressions  which  are  so  visible 
hr  the  parietal  bone.  It  generally  divides  into  two  great 
branches:  the  anterior,  which  is  the  largest,  passes  over 
the  anterior  and  inferior  angle  of  the  parietal  bone:  the 
posterior  branch  soon  divides  into  many  ramifications, 
which  are  extended  laterally  and  posteriorly. 

It  furnishes  the  twig  which  passes  to  the  ear  by  the 
hiatus  of  Fallopius,  and  anastomoses  with  the  small 
branches  of  the  stylo  mastoid  artery. 

It  also  supplies  some  other  small  vessels  which  pass  to 
the  cavity  of  the  tympanum  by  small  foramina  near  the 
junction  of  the  squamous  and  petrous  portions  of  the 
temporal  bone. 

d.  The  next  branch  sent  off  by  the  internal  maxillary 
leaves  it  about  an  inch  from  its  origin,  and  is  called  the 
Inferior  Maxillary.  It  passes  between  the  internal  ptery- 

subject,  if  he  should  undertake  the  management  of  necrosis  of  the 
jaw  bones;  or  of  those  fungous  tumours,  which  sometimes  originate 
in  the  antrum  maxillare;  as  well  as  of  several  other  complaints. 


238  The  Internal  Maxillary  Artery. 

goid  muscle  and  the  bone,  and  after  giving  small  branches 
to  the  contiguous  muscles,  enters  the  canal  in  the  lower 
jaw,  in  company  with  the  nerve.  This  canal  has  a very 
free  communication  with  the  cellular  structure  of  the 
jaw,  and  the  artery  in  its  progress  along  it  sends  branches 
to  the  respective  teeth  and  the  bone.  At  the  anterior 
maxillary  foramen,  this  artery  sends  olf  a considerable 
branch,  which  passes  out  and  anastomoses  with  the  ves- 
sels on  the  chin,  while  another  branch  passes  forward 
and  supplies  the  canine  and  incisor  teeth  and  the  bone 
contiguous  to  them. 

Sometimes  the  inferior  maxillary  artery  divides  into 
two  branches  before  it  has  arrived  at  this  foramen.  In* 
this  case,  one  of  the  arteries  passes  out  of  the  foramen, 
while  the  other  continues  to  the  symphysis. 

e.  Two  branches  pass  off  to  the  temporal  muscle, 
which  originate  at  a small  distance  from  each  other:  one 
of  them  passes  upwards  on  the  tendon  of  the  temporal 
muscle;  the  other  arises  near  the  tuberosity  of  the  upper 
maxillary  bone:  they  are  called  the  exterior  deepy  and 
the  interior  deep  temporal  artery . They  are  both  spent 
upon  the  temporal  muscle;  but  the  interior  branch  sends 
a small  twig  into  the  orbit  of  the  eye. 

f.  There  are  some  small  branches  which  pass  to  the 
Pterygoid  Muscles  and  to  the  Masseter , which  arise 
either  from  the  internal  maxillary  artery,  or  from  the  an- 
terior deep  temporal.  They  are  generally  small,  and  often 
irregular. 

c.  An  artery,  particularly  appropriated  to  the  cheek, 
perforates  the  buccinator  muscle  from  within  outwards, 
and  generally  terminates  on  the  buccinator,  the  zygoma- 
ticus  major  and  the  muscles  of  the  lips.  This  Artery  oj 
the  Cheelc  is  very  irregular  in  its  origin,  sometimes  aris- 
ing from  the  internal  maxillary,  sometimes  from  the 
deep  temporal,  and  sometimes  from  the  suborbitary,  or 
from  the  alveolar  artery,  to  be  immediately  described. 


The  Internal  Maxillary  Artery.  239 

h.  The  Alveolar  Artery , or  the  Artery  of  the  Upper 
Jaw , arises  generally  from  the  internal  maxillary,  but 
sometimes  from  one  of  its  branches.  It  winds  round  the 
tuberosity  of  the  upper  jaw,  and  sends  branches  to  the 
buccinator  muscle,  to  the  bone  and  the  gums,  to  the  an- 
trum highmorianum,  and  some  of  the  molar  teeth:  and 
also  to  the  teeth  generally,  by  means  of  a canal  which  is 
analogous  to  that  of  the  lower  jaw. 

i.  The  Infra- orhitar  Artery  arises  from  the  internal 
maxillary  in  the  zygomatic  fossa,  and  soon  enters  the 
infra  orbitary  canal,  through  which  it  passes  to  the  face, 
and  emerges  below  the  orbit  of  the  eye,  supplying  the 
muscles  in  the  vicinity,  and  anastomosing  with  the  small 
ramifications  of  the  two  last  described  arteries,  and  also 
of  the  facial  artery  and  the  ophthalmic. 

This  artery  in  its  course  sends  off  small  twigs  to  the 
periosteum,  the  adipose  membrane,  and  the  muscles 
in  the  inferior  part  of  the  orbit,  and  also  to  the  great 
maxillary  sinus  or  antrum  highmorianum,  and  to  the  ca- 
nine and  incisor  teeth. 

j.  The  Palato  Maxillary , or  Superior  Palatine  Artery, 
arises  also  in  the  zygomatic  fossa,  and,  descending  be- 
hind the  upper  maxillary  bone,  enters  the  posterior  pala- 
tine canal.  It  generally  forms  two  branches,  the  largest 
of  which  advances  forward,  supplying  the  palate  and 
gums,  and  finally  sends  a twig  through  the  foramen  in- 
cisivum  to  the  nose,  while  the  posterior  branch,  which 
is  much  smaller,  supplies  the  velum  pendulum  palati. 

ic.  The  Pterygo  Palatine,  or  Superior  Pharyngeal , is 
a small  vessel,  which  sometimes  arises  from  the  artery- 
next  to  be  mentioned.  It  is  spent  upon  the  upper  part  of 
the  pharynx,  and  a branch  passes  through  the  pterygo 
palatine  foramen,  which  is  spent  upon  the  arch  of  the 
palate  and  the  contiguous  parts. 

l.  The  internal  maxillary  at  length  terminates 
in  the  Spheno- Palatine,  or  Large  Nasal  Artery,  which 


240  Temporal  Artery. 

passes  through  the  spheno-palatine  foramen  to  the  back 
part  of  the  nose.  This  artery  sometimes  separates  into 
two  branches  before  it  enters  the  foramen;  sometimes  it 
enters  singly,  and  divides  into  two  branches  soon  after; 
one  of  them  is  spread  upon  the  septum,  and  the  other 
upon  the  external  side  of  the  nose;  each  of  these  branches 
ramifies  very  minutely  upon  the  Schneiderian  membrane 
and  its  process  in  the  different  sinuses,  and  also  in  the 
ethmoidal  cells. 


8.  The  TEMPORAL  ARTERY 

Is  considered  as  the  continuation  of  the  external  carotid, 
because  it  preserves  the  direction  of  the  main  trunk,  al- 
though the  internal  maxillary  is  larger. 

After  parting  with  the  internal  maxillary  it  projects  out- 
wards; and  passing  between  the  Meatus  Auditorius  Ex- 
ternus  and  the  condyle  of  the  lower  jaw,  continues  up- 
wards, behind  the  root  of  the  zygomatic  process  of  the 
temporal  bone,  to  the  aponeurosis  of  the  temporal  muscle: 
on  the  outside  of  which,  immediately  under  the  integu- 
ments, it  divides  into  two  large  branches  denominated 
anterior  and  posterior. 

Before  this  division  the  temporal  artery  sends  off  seve- 
ral branches  of  very  different  sizes. 

One,  which  is  considerable  in  size,  and  called  the 
Transverse  Facial  Branch , advances  forwards  across  the 
neck  of  the  condyle  of  the  lower  jaw,  and  giving  small 
branches  to  the  masseter,  runs  parallel  to  the  parotid  duct, 
and  below  it.  This  branch  is  spent  upon  the  muscles  of 
the  face,  and  anastomoses  with  the  other  vessels  of  that 
part. 

The  temporal  gives  off  small  branches  to  the  parotid 
gland  and  to  the  articulation  of  the  jaw.  From  the  last 
mentioned  branch  small  twigs  pass  to  the  ear,  one  of 


Temporal  Artery.  Internal  Carotid.  241 

which  enters  the  cavity  of  the  tympanum  by  the  glenoid 
fissure. 

While  this  artery  is  on  a line  with  the  zygoma,  it 
sends  off  a branch  called  the  middle  temporal  artery , which 
penetrates  the  aponeurosis  of  the  temporal  muscle,  and 
ramifies  under  it  upon  the  muscle  in  an  anterior  direc- 
tion. 

The  two  great  branches  of  the  temporal  artery  are  dis- 
tributed in  the  following  manner.  The  Anterior  passes  up 
in  a serpentine  direction  on  the  anterior  part  of  the  tem- 
ple, and  supplies  the  front  side  of  the  head,  and  the  upper 
part  of  the  forehead. 

The  Posterior  extends  upwards  and  backwards,  and 
supplies  the  scalp  on  the  lateral  and  middle  part  of  the 
cranium,  and  also  the  bone. 

Ramifications  from  each  of  these  branches  anastomose 
on  the  upper  part  of  the  cranium  with  those  of  its  fellow 
of  the  opposite  side.  The  anterior  branch  also  anastomo- 
ses on  the  forehead  with  the  facial  and  ophthalmic  artery; 
and  the  posterior  branch  with  the  occipital  artery  on  the 
back  part  of  the  head. 

THE  INTERNAL  CAROTID  ARTERY 

Is  sometimes  called  the  Artery  of  the  Brain , as  it  is 
almost  entirely  appropriated  to  that  viscus. 

From  its  origin  to  the  commencement  of  its  ramifica- 
tions the  course  of  this  bloodvessel  is  peculiarly  tortuous. 
In  consequence  of  which,  the  force  of  the  blood  in  it  is 
greatly  diminished  before  it  arrives  at  the  brain. 

An  instance  of  this  curvature  occurs  immediately 
after  its  separation  from  the  external  carotid,  when  it  pro- 
trudes outwards  so  much  as  to  be  exterior  to  that  vessel; 
after  this,  it  ascends  to  the  carotid  canal,  and  in  its  course 
is  in  contact,  or  very  near  the  par  vagum  and  intercos- 
tal nerves. 

Vol.  IL 


2H 


242  Curvatures  of  the  Internal  Carotid. 

The  carotid  canal  in  the  os  petrosum  is  by  no  means 
straight;  it  forms  a semicircular  curve,  forwards  and  in- 
wards; and  its  upper  portion,  which  is  nearly  horizontal, 
opens  obliquely  against  the  body  of  the  sphenoidal  bone 
at  a small  distance  from  it.  Therefore,  after  the  artery 
has  passed  through  the  canal,  it  must  turn  upwards  to 
get  fairly  into  the  cavity  of  the  cranium;  and  of  course, 
its  direction  while  in  the  canal,  forms  almost  a right  angle 
with  its  direction  before  it  enters,  and  after  it  emerges 
from  it. 

In  consequence  of  this  curvature,  much  of  the  mo- 
mentum of  the  blood  must  be  impressed  upon  the  cra- 
nium. 

After  the  artery  has  arrived  at  the  end  of  the  carotid 
canal,  and  has  turned  upwards  to  get  within  the  cavity  of 
the  cranium,  it  bends  forwards,  and  passes  nearly  in  a 
horizontal  direction,  through  the  cavernous  sinus  on  the 
side  of  the  sella  turcica,  to  the  anterior  clinoid  process; 
here  it  again  forms  a considerable  curve,  which  is  directly 
upwards,  and  then  it  perforates  the  dura  mater. 

These  curvatures  must  also  deprive  the  blood  of  the 
carotid  of  a portion  of  the  momentum  which  it  has  re- 
tained after  leaving  the  bone. 

The  object  of  these  various  flexures  of  the  internal  ca- 
rotid appears  to  be  analogous  to  that  of  the  Pete  Mira- 
bile  in  certain  quadrupeds,  which  is  formed  by  the  divi- 
sion of  this  artery  into  many  small  branches,  that  reunite 
again,  without  producing  any  other  effect  than  the  dimi- 
nution of  the  momentum  of  the  blood. 

During  its  course  from  the  place  of  bifurcation  to  its 
entrance  into  the  carotid  canal,  the  internal  carotid  arte- 
rv  very  rarely  sends  off  any  branches.  In  the  canal  it 
gives  off  a small  twig  which  enters  the  cavity  of  the  tym- 
panum; and  sometimes  a second  which  unites  with  the 
Pterygoid  branch  of  the  internal'maxillary. 

As  it  goes  by  the  sella  turcica,  it  passes  through  the 


243 


Ophthalmic  Artery. 

cavernous  sinuses,  and  gives  off  two  branches  which  are 
called  the  Posterior  and  Anterior  arteries  of  the  Caver - 
nous  Sinus  or  Receptacle. 

The  posterior  branch  goes  to  that  part  of  the  dura  ma- 
ter which  is  connected  with  the  posterior  clinoid  process, 
and  the  cuneiform  process  of  the  occipital  bone.  It  like- 
wise gives  branches  to  several  of  the  nerves  which  are 
contiguous,  and  to  the  pituitary  gland. 

The  anterior  artery  also  gives  branches  to  the  conti- 
guous nerves,  to  the  dura  mater,  and  the  pituitary  gland. 

When  the  internal  carotid  turns  upwards  at  the  anterior 
clinoid  process,  it  sends  off  the 

OPHTHALMIC  ARTERY, 

Which  passes  under  the  optic  nerve  through  the  foramen 
opticum  into  the  orbit  of  the  eye,  and  is  about  two  lines 
in  diameter. 

Although  this  artery  enters  the  orbit  under  the  optic 
nerve,  it  soon  takes  a position  on  the  outside  of  it;  but 
afterwards  gradually  proceeds  to  the  inner  side  of  the 
orbit,  crossing  over  this  nerve  in  an  oblique  direction,  and 
finally  passes  out  of  the  orbit  near  the  internal  angle.  In 
this  spiral  course  it  sends  off  numerous  branches,  viz. 

a.  To  those  parts  which  are  auxiliary  to  the  eye. 

b.  To  the  ball  of  the  eye. 

c.  To  the  cavity  of  the  nose,  through  small  foramina 
in  the  ethmoid  bone,  and 

d.  To  the  forehead  and  external  side  of  the  nose. 

These  branches  generally  go  off  in  the  following  order. 

The  Lachrymal  artery  arises  soon  after  the  ophthal- 
mic arrives  within  the  orbit,  and  passes  above  the  abduc- 
tor muscle  to  the  lachrymal  gland,  where  it  terminates, 
sending  off  many  small  branches  in  its  course. 

The  Central  artery  of  the  retina  also  leaves  the  ophthal- 
mic soon  after  its  arrival  in  the  orbit:  it  is  a small  vessel 


244  Branches  of  the  Ophthalmic  Artery . 

which  penetrates  into  the  center  of  the  optic  nerve,  and 
passing  with  it  into  the  eye  is  spread  upon  the  internal 
surface  of  the  retina.  Here  it  appears  to  terminate  in  the 
adult;  but  in  the  foetus  it  is  continued  through  the  vitreous 
humour  to  the  capsule  of  the  crystalline  lens. 

While  the  ophthalmic  is  passing  over  the  optic  nerve 
the  branches  which  enter  the  ball  of  the  eye  leave  it. 
Their  number  varies,  but  they  form  three  classes,  viz. 
The  Long  Ciliary , the  Short  Ciliary , and  the  Anterior 
Ciliary  arteries.  (See  description  of  the  eye,  vol.  i.  p.  341.) 
The  supra  orbitary  and  muscular  branches  leave  it  also 
near  the  same  places. 

The  Supra  Orbitary  Branch  often  gives  off  several 
muscular  twigs:  but  it  passes  out  of  the  orbit  through  the 
supra  orbitar  foramen,  and  generally  divides  into  two 
branches,  one  of  which  is  spent  upon  the  periosteum,  and 
the  other  upon  the-skin  and  muscles  of  the  forehead. 

There  are  sometimes  two  muscular  branches , a Superior 
and  an  Inferior.  The  superior  branch  is  often  deficient: 
when  it  exists  it  supplies  the  levator  palpebrse,  the  levator 
oculi,  obliquus  superior,  See.;  but  these  parts  are  often 
supplied  by  the  branches  above  mentioned.  The  supra 
orbitar  so  frequently  gives  off  branches  to  the  muscles  that 
it  has  been  called  the  Superior  Muscular  Branch.  The 
inferior  muscular  branch  is  more  constant.  It  commonly 
supplies  the  rectus  inferior,  the  adductor,  and  the  inferior 
oblique  muscles,  and  also  the  lachrymal  sac,  and  the  low- 
er eyelid,  &c. 

When  the  artery  is  on  the  inside  of  the  nerve  it  sends 
off  'he  two  branches  to  the  cavity  of  the  nose,  viz.  The 
Ethmoidal  Arteries;  and  also,  branches  to  the  eyelids. 

The  Posterior  Ethmoidal  branch  is  first.  It  passes  be- 
tween the  levator  and  adductor  muscles,  and  above  the 
obli  juus  superior;  and  penetrates  the  cavity  of  the  crani- 
um by  the  posterior  orbitary  foramen:  after  giving  some 
twigs  to  the  dura  mater,  it  passes  to  the  posterior  cells 


Branches  of  the  Ophthalmic  Artery . 245 

of  the  ethmoid  by  the  foramina  of  the  cribriform  plate 
of  that  bone,  and  sends  a small  branch  to  the  Schneide- 
rian membrane  on  the  back  part  of  the  septum  of  the  nose. 

The  Anterior  Ethmoidal  artery  arises  from  the  ophthal- 
mic nearly  opposite  to  the  anterior  orbitary  foramen, 
through  which  it  passes:  and  after  entering  the  cranium 
is  distributed  like  the  other  through  some  of  the  foramina 
of  the  cribriform  plate  to  the  anterior  cells  of  the  ethmoid 
bone,  and  to  the  anterior  part  of  the  Schneiderian  mem- 
brane on  the  septum  of  the  nose,  to  which  it  sends  a 
considerable  branch. 

In  its  course  it  sends  twigs  to  the  frontal  sinuses,  and 
to  the  dura  mater  and  its  falciform  process. 

The  arteries  of  the  Palpebrce  are  called  Superior  and 
Inferior;  they  leave  the  ophthalmic  near  the  loop  or  pully 
of  the  superior  oblique  muscle.  The  inferior  comes  off 
first;  it  sends  branches  to  the  ligaments  of  the  tarsus,  the 
caruncula  lachrymalis,  and  the  parts  connected  with  the 
cartilage  of  the  under  eyelid,  and  unites  with  the  lachry- 
mal artery  near  the  external  canthus,  forming  an  arch 
called  the  Inferior  Tarsal  Arch. 

The  Superior  Artery  supplies  the  superior  part  of  the 
orbicularis  muscle,  the  ligament  and  caruncula  also:  and 
it  likewise  unites  with  a twig  of  the  lachrymal,  and  forms 
the  superior  tarsal  arch. 

Soon  after  sending  off  the  palpebral  branches,  the 
Ophthalmic  Artery  arrives  at  the  internal  canthus,  and 
then  finally  divides  into  two  branches,  the  nasal  and  the 
frontal. 

The  Nasal  Branch  passes  above  the  superior  part  of 
the  lachrymal  sac  and  the  ligament  of  the  eyelid  to  the 
nose;  after  sending  a twig  to  the  frontal  muscle  and  the 
lachrymal  sac,  it  passes  down  the  side  of  the  nose  and 
anastomoses  with  the  facial  artery. 

The  Frontal  Artery  is  not  so  large  as  the  nasal;  it  gene- 
rally divides  into  three  parts.  A superciliary  branch  which 


246  Internal  Carotid.  Middle  Artery  of  the  Brain. 

is  principally  spent  upon  the  eyebrows;  a superficial 
branch  which  is  spent  upon  the  forehead;  and  a branch 
which  is  distributed  to  the  pericranium. 

The  INTERNAL  CAROTID , soon  after  parting  with 
the  ophthalmic,  sends  off,  in  a posterior  direction,  a branch 
to  join  one  from  the  vertebral  artery.  From  its  destination 
this  vessel  is  called  the  arteria  communicans. 

After  this  it  sends  off  another  branch,  which  is  so  large 
that  it  may  be  considered  as  a continuation  of  the  main 
trunk:  this  is  called  the  middle  artery  of  the  brain, 
or  the  arteria  sylviana.  It  runs  outwards  nearly  in 
the  direction  of  the  fossa  Sylvii,  which  separates  the  an- 
terior from  the  middle  lobes  of  the  cerebrum.  In  its  course 
it  divides  and  subdivides  into  numerous  branches  which 
are  spread  upon  the  Pia  Mater , and  finally  enter  the 
surface  of  the  brain  in  a very  minute  state. 

The  internal  carotid  then  terminates  in  a branch  which 
is  smaller  than  the  last  mentioned,  and  from  its  situation 
is  called  the  anterior  artery  of  the  brain,  or  ar- 
teria callosa.  This  vessel  first  inclines  towards  its 
fellow  on  the  opposite  side,  and  after  approaching  within 
half  an  inch  of  it,  forms  another  curve,  and  runs  forward 
to  the  anterior  part  of  the  brain,  dividing  itself  gradually 
into  branches  which  pass  in  several  directions. 

When  these  anterior  arteries  are  nearest  to  each  other, 
a small  Transverse  branch,  which  passes  at  right  angles, 
connects  them  together.  This  branch  completes  the  ante- 
rior part  of  the  Circle  of  Willis.  It  crosses  immediately 
before  the  sella  turcica  and  pituitary  gland,  and  sends  off 
branches  which  pass  to  the  third  ventricle,  to  the  fornix 
and  septum  lucidum,  and  also  to  the  pia  mater. 

The  anterior  arteries  of  the  brain  also  send  off 
branches  to  the  optic  and  olfactory  nerves;  to  the  opposite 
surfaces  of  the  two  hemispheres  on  each  side  of  the  falx; 
to  their  inferior  surfaces,  and  to  the  corpus  callosum. 

They  have  likewise  some  branches  which  anastomose 


247 


Right  and  Left  Subclavian  Arteries. 

with  those  of  the  middle  artery  of  the  brain,  and  of  the 
vertebral  artery. 

The  SUBCLAVIAN  Arteries. 

The  RIGHT  SUBCLAVIAN  may  be  considered  as 
the  continuation  of  the  arteria  innominata.  This  last 
mentioned  artery,  after  leaving  the  aorta,  forms  a curve 
or  arch,  which  extends  obliquely  backwards  and  out- 
wards, over  the  first  rib  to  the  axilla,  crossing  the  trachea 
in  its  course.  At  the  distance  of  an  inch  and  a quarter,  or 
an  inch  and  a half  from  its  origin,  it  sends  off  the  right 
carotid,  and  then,  assuming  the  name  of  Right  Subclavian , 
continues  in  the  above  stated  direction. 

The  cord  of  the  curve  of  this  artery,  and  the  cord  of 
the  curve  of  the  aorta,  are  not  in  the  same  direction,  but 
form  an  angle  with  each  other. 

The  position  of  the  LEFT  SUBCLAVIAN  is  some- 
what different  from  that  of  the  right.  Its  origin  is  poste- 
rior, and,  therefore,  the  direction  of  the  cord  of  its  curve  is 
more  immediately  lateral.  The  curve  or  arch  is  also  smal- 
ler. The  situation  of  the  two  subclavians  as  relative  to 
the  contiguous  parts,  is,  therefore,  somewhat  different; 
but  each  of  them  proceeds  between  the  anterior  and  the 
middle  scaleni  muscles,  and  when  they  have  arrived  at 
these  muscles,  their  respective  positions  are  very  similar. 

The  anterior  and  middle  scaleni  muscles  arise  from  the 
transverse  processes  of  several  of  the  cervical  vertebras, 
and  are  inserted  into  the  first  rib,  one  before  the  other,  so 
as  to  leave  a considerable  space  between  them.  The  sub- 
clavian arteries  pass  through  this  space,  and  before  they 
arrive  at  it,  but  when  they  are  very  near  the  above  men- 
tioned muscles,  they  send  off  several  very  important 
branches  in  various  directions,  viz.  to  the  cavity  of  the 
cranium,  to  the  parietes  of  the  thorax,  to  the  thyroid 
gland,  and  to  the  lower  part  of  the  neck. 


248  Course  and  Distribution  of  the  Inferior 

They  proceed  near  to  the  scaleni  muscles  before  they 
send  off  any  branches;  and  it  is  to  be  observed,  that  the 
subclavian  veins  which  correspond  with  these  arteries, 
are  anterior  to  them,  for  they  pass  before  the  scaleni 
muscles,  and  not  between  them. 


The  internal  mammary  Artery 

Goes  downwards,  from  the  lower  and  anterior  part  of  the 
subclavian,  along  the  inner  side  of  the  anterior  scalenus 
muscle.  It  proceeds,  exterior  to  the  pleura,  across  the  car- 
tilages of  the  true  ribs,  and  near  their  middle;  and,  con- 
tinuing between  the  cartilages  and  the  diaphragm,  exterior 
to  the  peritoneum,  terminates  on  the  rectus  abdominis 
muscle,  in  branches  which  anastomose  with  those  of  the 
epigastric  artery.  In  this  course  it  gives  branches  to  al- 
most all  the  parts  to  which  it  is  contiguous,  viz.  to  the 
muscles  and  glands  at  the  lower  part  of  the  neck;  to  the 
thymus  gland;  to  the  parts  in  the  intercostal  spaces;  to  the 
sternum;  to  the  mediastinum  and  pericardium;  to  the 
diaphragm  and  to  the  muscles  of  the  abdomen. 

From  some  of  its  ramifications  upon  the  parts  between 
the  ribs,  small  branches  go  off  to  the  mamma,  and  thereby 
give  a name  to  the  artery.  There  is  also  a small  vessel 
which  is  sent  off  by  the  mammary  artery,  or  by  one  of  its 
upper  branches,  which  accompanies  the  phrenic  nerve  to 
the  diaphragm. 


The  inferior  thyroid  Artery 

Arises  from  the  upper  side  of  the  subclavian  nearly  op- 
posite to  the  origin  of  the  internal  mammary.  It  passes 
upwards  and  inwards,  between  the  carotid  artery  and  the 
spine,  to  the  thyroid  gland:  then  it  anastomoses  with  the 


Thyroid  and  the  Vertebral  Arteries.  249 

branches  of  the  superior  thyroid  on  the  same  side,  and 
with  those  of  its  fellow  on  the  opposite  side. 

This  vessel  sometimes  sends  off  large  branches  to  the 
muscles  at  the  lower  part  of  the  neck. 

The  vertebral  Artery 

Arises  from  the  upper  and  posterior  part  of  the  subclavian. 
It  goes  upwards  and  backwards  between  the  muscles  which 
lie  on  the  front  of  the  spine,  and  passing  under  the  trans- 
verse process  of  the  sixth  or  seventh  cervical  vertebra, 
enters  into  the  canal  formed  in  the  transverse  processes 
of  the  vertebrae.  In  this  course,  as  it  proceeds  from  the 
third  to  the  second  cervical  vertebra,  it  inclines  outwards 
laterally,  and,  in  its  passage  from  the  transverse  process 
of  the  second  to  that  of  the  first  vertebra,  it  forms  a con- 
siderable curve,  the  convexity  of  which  has  a lateral  and 
external  aspect.  After  passing  the  transverse  process  of 
the  Atlas , it  is  turned  suddenly  backwards,  in  a groove, 
and  finally  passes  through  the  great  occipital  foramen  into 
the  cavity  of  the  cranium.  It  then  proceeds  upon  the  cu- 
neiform process  of  the  occipital  bone,  under  the  Medulla 
Oblongata , and  joins  its  fellow  so  as  to  form  an  acute  angle 
with  it  near  the  union  of  the  medulla  oblongata  with  the 
pons  Varolii.  From  each  of  the  vertebral  arteries,  before 
their  union,  there  generally  goes  off  a small  branch  called 
the  Posterior  Meningeal , which  is  spent  upon  the  posterior 
part  of  the  dura  mater. 

The  trunk  formed  by  the  union  of  the  vertebral  arteries 
is  called 


The  BASILAR  Artery. 

It  extends  forward  near  to  the  anterior  part  of  the  pons 
Varolii,  where  it  bifurcates;  but  previously  sends  off  se- 
veral branches  on  each  side.  The  first  pair  go  off  in  a 
Vol.  II.  2 I 


250 


Basilar  Artery. 

lateral  direction,  soon  after  its  commencement,  near  the 
back  part  of  the  pons  Varolii,  and  are  spent  upon  the  me- 
dulla oblongata,  the  pons  Varolii.  and  'he  other  contigu- 
ous parts,  and  also  upon  the  fourth  ventricle  and  the  Plex- 
us Choroides  of  that  cavity.  They  are  called  the  Posterior 
or  Inferior  Arteries  of  the  Cerebellum. 

Two  other  lateral  branches,  which  are  called  the  Su - 
perior  Arteries  of  the  Cerebellum , go  oft' from  the  basilar 
artery,  near  its  anterior  extremity.  These  are  principally 
spent  upon  the  crura  of  the  cerebellum  and  cerebrum; 
upon  the  cerebellum  itself,  and  the  contiguous  parts. 

Soon  after  sending  oft’  the  last  mentioned  arteries,  the 
basilar  artery  divides  into  two  branches,  which  also 
take  a lateral  direction,  and  are  of  considerable  size.  In 
their  course  outward,  these  branches  are  curved  with 
their  convexity  forward.  About  ten  or  twelve  lines  from 
its  commencement,  each  of  them  sends  off  a branch  called 
the  arteria  communicans,  which  passes  directly  for- 
ward, and  communicates  with  the  internal  carotid,  thus 
forming  the  arrangement,  which  is  called  the  Circle  of 
Willis .*  After  sending  off  these  arteries,  they  continue 
their  lateral  direction,  and  are  distributed  principally  to 
the  posterior  parts  of  the  cerebrum.  These  terminating 
branches  of  the  basilar  artery  are  called  the  Poste- 
rior Arteries  of  the  Cerebrum. 

* The  arteria  communicans  is  also  considered  as  a branch  of  the 
Internal  Carotid.  The  arrangement  here  alluded  to  is  very  remark- 
able. As  the  branches  which  pass  off  laterally  from  the  single  trunk 
of  the  Basilar  Artery  unite  to  the  Internal  Carotids,  and  the  Internal 
Carotids  are  united  to  each  other,  there  is  an  uninterrupted  conti- 
nuation of  artery,  which  incloses  a portion  of  space  of  a determined 
form;  but  this  form  resembles  an  oblong  square  more  than  a circle. 
By  this  connexion  blood  will  pass  from  any  one  of  the  four  arteries 
of  the  brain  to  all  the  others. 


Arteries  of  the  lower  part  of  the  Neck.  251 


The  superior  intercostal  Artery 

Arises  from  the  upper  part  of  the  Subclavian , after  the 
Vertebral  and  Thyroid  arteries,  and  very  near  them.  It  de- 
scends by  the  side  of  the  spine  across  the  first  and  second 
ribs,  near  their  heads,  and  exterior  to  the  great  intercostal 
nerve . It  generally  forms  two  branches,  which  are  ap- 
propriated to  the  muscles,  & c.,  in  the  first  and  second 
intercostal  spaces,  and  sometimes  a small  branch  is  con- 
tinued to  the  third  intercostal  space.  From  each  of  these 
branches  a small  vessel  proceeds  backwards,  and  is  spent 
upon  the  contiguous  muscles,  &c.,  on  the  back  of  the 
thorax.  The  intercostal  artery  also  sends  a branch 
upwards  to  the  deep  seated  parts  of  the  neck. 

In  addition  to  the  arteries  above  mentioned,  there  are 
several  others  of  considerable  size,  which  originate  either 
directly  or  indirectly  from  the  SUBCLAVIAN ’ and  are 
spent  upon  the  lower  portion  of  the  neck,  and  the  conti- 
guous parts.  These  arteries  are  very  different  in  different 
subjects,  especially  as  to  their  origin.  Two  of  them,  which 
have  been  called  the  anterior  and  posterior  cervi- 
CALS,are  generally  distributed  to  the  muscles  and  other 
parts  which  lie  on  the  lower  portion  of  the  neck  anteriorly 
and  posteriorly. 

A third,  which  passes  transversely  on  the  lower  part  of 
the  neck,  is  called  the  superior  scapular. 

In  some  cases  the  two  cervical  arteries  arise  from 
the  subclavian,  after  the  mammary  and  the  thyroid,  in  a 
common  trunk,  which  soon  divides.  Very  frequently 
they  go  off  from  the  Inferior  Thyroid.  Sometimes  one  of 
them  goes  off  from  the  Inferior  Thyroid , and  the  other 
from  one  of  the  branches  of  the  Subclavian .* 

* Haller  paid  great  attention  to  the  arterial  system,  and  made 
many  dissections,  with  a view  to  engravings  of  it,  which  he  publish- 
ed with  descriptions,  in  folio  fasciculi. 


These 


25  2 


Branches  that  go  off  in  the  Axilla . 

The  Superior  Scapular  most  commonly  arises  with 
some  other  artery,  and  very  often  from  the  Inferior 
Thyroid.  It  runs  transversely  outwards,  within  and  above 
the  clavicle,  and  passing  through  the  notch  in  the  upper 
costa  of  the  scapula,  divides  into  branches  which  are  dis- 
tributed to  the  parts  on  the  dorsum  of  that  bone. 

The  SUBCLAVIAN  ARTERY , in  its  progress  from 
the  aorta  to  the  axilla,  forms  an  arch  or  curve,  over  the 
first  rib,  as  has  been  already  observed.  The  anterior 
scalenus  muscle  is  before  it,  and  the  great  nerves  of  the 
upper  extremity  are  above  it.  After  passing  between  the 
scaleni  it  descends  upon  the  first  and  second  rib  into  the 
axilla.  The  nerves  which  were  above,  descend  with  it: 
at  first  they  are  necessarily  exterior  to  it,  but  they  form  a 
plexus  which  the  artery  enters  into,  so  as  to  be  partly 
surrounded  by  them.  This  course  of  the  artery  is  ob- 
liquely under  the  clavicle,  and  behind  the  pectoral  muscle. 
In  the  axilla,  the  vessel  and  nerves  which  surround  it  are 
placed  between  the  tendons  of  the  pectoralis  and  the 
latissimus  dorsi  muscles.  Here  the  artery  takes  the  name 
of  AXILLARY,  and  sends  off  several  important  branches. 

The  principal  branches  that  go  off  from  the  axillary 
artery  are  distributed 

1st.  Anteriorly,  to  the  pectoral  muscle,  and  the  parts 
on  the  anterior  surface  of  the  thorax. 

2d.  Posteriorly,  to  the  muscles  which  are  on  the  sca- 
pula and  contiguous  to  it;  and 

3d.  To  the  parts  which  are  near  the  upper  extremity  of 
the  os  humeri. 

These  fasciculi  have  been  collected,  and,  with  some  other  engrav- 
ings, form  a large  volume,  entitled  ICONES  ANATOMICJL, 
which  is  truly  valuable. 

There  are  some  very  interesting  observations  on  this  work  of  Hal- 
ler’s, and  also  on  these  arteries,  in  a DESCRIPTION  OF  THE 
ARTERIES,  by  Dr.  Barclay  of  Edinburgh,  which  I have  read  with 
advantage,  as  well  as  a work  on  the  muscles  by  the  same  author. 


Branches  that  go  off  in  the  Axilla. 


253 


Anterior  Branches. 


The  arteries  which  go  to  the  pectoral  muscle,  &c.,  are 
very  various  in  different  subjects,  both  as  to  their  number, 
origin,  and  size. 

They  have  also  been  called  by  different  names,  as 

THORACIC AL,  MAMMARI®  EXTERNAL,  be. 

There  are  almost  always  three  of  them,  and  very  often 
more;  one  of  them,  which  is  called  by  several  authors  the 
Acromialis,  proceeds  towards  the  end  of  the  clavicle,  and 
generally  passes  out  at  the  interval  between  the  deltoid 
and  the  pectoral  muscle,  sending  various  branches  to  the 
contiguous  parts;  the  largest  of  its  branches  often  passing 
in  the  direction  of  the  interstice  between  those  muscles. 

Another  of  these  arteries,  which  is  called  Superior 
Thoracic , is  generally  very  small:  it  often  is  a branch 
of  the  above  mentioned  Acromialis. 

There  is  very  often  to  be  found  here  an  artery  called 
the  Inferior  Thoracic , or  the  External  Mammary , which 
is  of  considerable  length,  although  its  diameter  is  not 
very  great.  This  artery  originates  near  the  two  last  men- 
tioned,  and  sometimes  from  the  Acromialis.  It  often  ex- 
tends downwards  as  low  as  the  sixth  rib,  and  send  branch- 
es to  the  anterior  part  of  the  thorax,  to  the  mamma,  and 
the  other  contiguous  parts.  Many  of  the  small  branches 
of  this  artery  anastomose  very  freely  with  those  of  the  in- 
ternal mammary. 

There  are  always  small  arterial  branches  in  the  axilla, 
which  ramify  upon  the  glands  and  adipose  matter  always 
existing  there.  They  often  arise  by  one  common  trunk, 
which  is  called  the  Axillary  Thoracic. 


Posterior  Branch. 

One  large  artery  is  commonly  sent  to  the  muscles  on 
the  scapula,  which  is  called  the  scapular,  the  common 


254 


Branches  that  go  off  in  the  Axilla. 

scapular,  or  the  internal  scapular.  It  commonly 
passes  off  from  the  axillary  after  the  thoracic  arteries, 
and  supplies  the  muscles  on  both  surfaces  of  the  scapula. 
This  large  vessel  passes  downwards  a short  distance  in 
the  direction  of  the  inferior  costa  of  the  scapula,  and  soon 
sends  off  a branch  that  winds  round  to  the  dorsum  of  the 
bone,  to  be  distributed  to  the  infra  spinatus  and  the  con- 
tiguous  muscles,  which  is  called  the  Dorsalis  Scapula. 
The  main  trunk  then  inclines  to  the  subscapularis  mus- 
cle, and  generally  divides  into  two  branches,  which  are 
distributed  to  the  subscapularis,  teres  major,  latissimus 
dorsi,  &c. 

Sometimes  the  scapular  artery  divides  into  two 
branches  before  it  sends  off  the  dorsal.  In  this  case  the 
last  mentioned  artery  goes  off  from  one  of  those  branches. 

Branches  near  the  Os  Humeri. 

The  arteries  which  are  near  the  body  of  the  os  humeri 
at  its  upper  end,  are  generally  two  in  number,  and  deno- 
minated the  Anterior  and  Posterior  Circumjlexce.  Some- 
times they  arise  separately,  and  sometimes  in  a common 
trunk  from  the  AXILLARY  artery.  Frequently  one  of 
them  arises  from  the  scapular. 

The  Anterior  Circumflex  passes  between  the  united 
heads  of  the  biceps  and  coraco  brachialis  muscles  and 
the  body  of  the  os  humeri,  at  a small  distance  below  its 
head.  It  sends  branches  to  the  capsular  ligament,  the  pe- 
riosteum of  the  os  humeri,  the  membranes  of  the  groove 
for  the  long  head  of  the  biceps,  the  upper  portions  of  the 
biceps  and  coraco  brachialis,  and  some  contiguous  mus- 
cles. 

The  Posterior  Circumflex  proceeds  between  the  sub- 
scapularis and  teres  major  muscles,  and  continues  be- 
tween the  os  humeri  and  the  head  of  the  triceps  and  the 


Situation  of  the  Humeral  Artery.  25  S 

deltoides.  It  is  distributed  to  the  muscles  and  parts  about 
the  joint,  especially  the  deltoides. 

These  arteries  surround  the  Os  humeri,  and  the  small 
branches  anastomose  with  each  other.  The  Posterior  Cir- 
cumflex is  much  larger  than  the  Anterior. 

The  great  artery  of  the  arm  proceeds  from  the  axilla 
to  the  elbow;  and,  during  this  course,  is  generally  deno- 
minated 

The  HUMERAL  Artery .*  ~ 

Its  direction  is  influenced  by  the  position  of  the  os  hu- 
meri. When  the  arm  hangs  down,  with  the  palm  of  the 
hand  presenting  forward,  this  direction  is  somewhat 
spiral.  The  situation  of  the  artery  is  on  the  inside  of  the 
biceps  muscle,  and  between  that  muscle  and  the  triceps 
extensor.  It  also  continues  very  near  and  on  the  inside 
- of  the  tendon  of  the  biceps,  and  under  the  Aponeurosis 
which  proceeds  from  that  tendon.  In  consequence  of  the 
spiral  or  oblique  course  of  the  artery,  its  direction  would 
be  from  the  inside  of  the  tendon  of  the  biceps  to  the  ra- 
dial side  of  the  fore  arm,  but  soon  after  it  passes  across 
the  joint  of  the  elbow,  it  divides  into  two  branches:  one 
which  preserves,  for  some  distance,  the  direction  of  the 
Main  Trunk , is  called  the  radial  artery:  the  other, 
which  inclines  obliquely  downwards  and  towards  the 
ulna,  is  the  common  trunk  of  the  ulnar  and  in- 
terosseal arteries. 

During  this  course,  the  HUMERAL  artery  sends  off 
several  branches  to  the  muscles  and  other  parts  on  the 
os  humeri.  The  largest  of  them  is  denominated  the  Pro-  * 
funda  Humeri , or  Spiralis.  This  artery  very  often  arises 
as  high  as  the  insertion  of  the  latissimus  dorsi,  and  pass- 
ing between  the  heads  of  the  triceps  extensor  muscle, 


* It  is  also  called  Brachial  Artery  by  several  writers. 


256 


Branches  of  the  Humeral  Artery. 

proceeds  downwards  under  that  muscle,  in  a spiral  di- 
rection, towards  the  external  or  radial  condy  le.  If  sends 
several  branches  to  the  triceps  and  ;he  contiguous  mus- 
cles, and  one  considerable  branch,  which  is  generally 
• called  the  Profunda  Minor , to  the  pai  fs  contiguous  to 
the  internal  condyle.  The  ramifications  of  these  branches 
near  the  condyle  frequently  anastomose  with  small 
branches  of  the  radial  and  ulnar  arteries.,* 

A small  branch  frequently  arises  from  he  humeral 
artery,  at  a short  distance  from  the  Profunda  Humeri , 
which  sends  a ramification  to  the  medullary  foramen  of 
the  os  humeri.  This  vessel  is,  therefore,  denominated 
Arteria  Nutritia. 

There  are  very  often  several  anastomoses  between  the 
branches  of  the  HUMERAL  artery,  which  originate 
above  the  elbow,  and  certain  branches  of  the  radial 
and  ulnar  arteries,  Which  are  called  from  their  direc- 
tion recurrents.  Among  these  arteries  there  is  generally 
one  of  considerable  size,  which  proceeds  across  the  elbow 
joint  near  the  internal  condyle.  Sometimes  this  is  the 
ulnar  recurrent,  which  goes  up  to  anastomose  with  the 
branches  of  the  profunda;  but  more  frequently  it  is  a 
separate  branch  of  the  HUMERAL  artery,  which  goes 
off  a little  above  the  elbow,  and  passes  across  the  articu- 
lation, near  the  internal  condyle,  to  anastomose  with  the 
branches  of  the  ulnar  artery.  This  artery  is  denominated 
the  Anastomotica. 

There  are  often  other  branches  sent  off  by  the  HU- 
MERAL artery;  but  they  are  commonly  small,  and  very 
irregular. 

The  two  great  ramifications  of  the  HUMERAL  artery 
on  the  fore  arm  have  very  different  directions.  The  ra- 

* The  Profunda  sometimes  originates  from  the  scapular,  or  one 
of  the  circumflex.  The  profunda  minor  sometime*  has  a distinct 
and  separate  origin,  lower  down  than  the  other. 


Course  ana  Ramifications  of  the  Radial  Artery.  257 

dial  artery  preserving  the  course  of  the  main  trunk, 
while  the  common  trunk  of  the  ulnar  and  interos- 
seal projects  from  it  in  a direction  downwards  and  to- 
wards the  ulna,  passing  under  the  pronator  teres,  &c. 

The  radial  Artery , 

Passing  over  the  pronator  teres  muscle,  proceeds  be- 
tween the  supinator  radii  longus  and  the  flexor  carpi  ra- 
dialis,  very  near  to  the  lower  end  of  the  radius,  without 
changing  its  direction  materially,  being  deep  seated 
above  and  superficial  below;  it  then  alters  its  course, 
and,  passing  under  the  tendons  of  the  extensors  of  the 
thumb,  to  the  back  part  of  the  radius,  it  continues  be- 
tween the  metacarpal  bones  of  the  thumb  and  of  the 
index  finger,  when  it  divides  into  three  branches. 

In  this  course  it  gives  off  but  few  branches.  The  first 
is  the  Radial  Recurrent , which  passes  upwards  and  to- 
wards the  external  condyle,  and  frequently  anastomoses 
with  the  ramifications  of  the  profunda  humeri. 

The  branches  which  it  sends  off  between  the  origin  of 
the  recurrent  and  the  lower  end  of  the  radius  are  gene- 
rally very  small,  and  distributed  to  the  parts  immediately 
contiguous  to  the  artery.  Before  it  turns  under  the  ten- 
dons of  the  extensors  of  the  thumb,  it  sends  a branch 
over  the  waist  towards  the  root  of  the  thumb,  from 
which  proceeds  a branch  to  anastomose  with  the  volar 
branch  of  the  ulnar;  and  another,  not  so  large,  which  is 
frequently  continued  on  the  radial  or  external  side  of  the 
thumb,  very  near  to  its  extremity.  While  the  radial  ar- 
tery is  under  the  aforesaid  tendons,  it  sends  off  small 
branches  to  the  back  of  the  wrist  and  back  of  the  hand, 
and  often  to  the  back  of  the  thumb.  Those  which  are 
distributed  to  the  wrist  and  back  of  the  hand,  generally 
anas  omose  with  the  small  branches  of  the  ulnar  and 
interosseal  arteries. 

Vol.  II.  2 K 


258  Origin  of  the  Ulnar  and  Interosseal  Arteries. 

The  three  branches  into  which  the  radial  artery 
divides  between  the  metacarpal  bones  of  the  thumb  and 
index  are,  1st.  a branch  to  the  external  side  of  the  index; 
2dly,  a branch  to  the  thumb , that  sometimes  divides  into 
two  which  pass  up  on  the  anterior  or  volar  surface,  and 
sometimes  continues,  without  much  diminution,  on  the 
internal  side  of  the  thumb,  near  to  the  end  of  the  last 
phalanx;  and,  3dly,  a branch,  called  Palmaris  Profunda , 
which  dips  down  into  the  palm  of  the  hand,  and,  pro- 
ceeding in  contact  with  the  metacarpal  bones,  under  the 
flexor  tendons,  &c.,  forms  an  arch  which  extends  across 
the  hand,  and  often  terminates  by  anastomosis  with  ano- 
ther arch,  soon  to  be  described,  which  is  formed  by  the 
ulnar  artery. 

This  flexure,  which  is  denominated  Arcus  Profundus , 
sends  off  branches  of  a very  small  size,  which  are  distri- 
buted to  the  bones,  ligaments,  muscles,  See.,  contiguous 
to  it. 

The  common  trunk  o/ the  ulnar  and  interosseal 

Arteries 

Passes  under  several  of  the  muscles  which  originate 
from  the  internal  condyle,  and  between  the  flexor  sub- 
limis  and  the  flexor  profundus.  Before  the  Ulnar  Recur- 
rent goes  off  from  this  vessel,  the  interosseal  artery 
often  leaves  it.  This  recurrent  artery  passes  upwards  be- 
tween the  muscles  of  the  internal  condyle,  and  distributes 
branches  among  them.  It  then  passes  up  in  the  groove 
behind  the  internal  condyle,  and  anastomoses  with  the 
branches  of  the  Anastomotica  or  Profunda  Humeri. 

The  ulnar  and  interosseal  arteries  separate  from  each 
other  at  the  distance  of  fifteen  or  twenty  lines  from  the 
origin  of  the  radial  artery,  very  near  the  commence- 
ment of  the  interosseal  ligament. 


Interosseal  and  Ulnar  Arteries. 


259 


The  interosseal  Artery , 

In  a majority  of  cases  arises  in  a single  branch  from  the 
common  trunk  of  the  ulnar  and  interosseal.  When  it  does 
so,  the  single  branch  soon  sends  off  the  Posterior  Inter- 
osseal artery,  which  perforates  the  interosseous  ligament, 
and  passes  down  on  its  posterior  surface,  while  the  main 
branch  continues  on  the  anterior  surface  of  the  ligament, 
and  is  denominated  the  Anterior  Interosseal  Artery . In 
some  cases  the  main  branch  proceeds  on  the  anterior 
surface  as  low  as  the  upper  edge  of  the  pronator  qua- 
dratus  muscle,  before  it  sends  off  the  posterior  branch. 
Sometimes  the  anterior  and  posterior  interosseals  arise 
separately.  In  this  case  the  posterior  soon  perforates  the 
ligament. 

The  Anterior  Interosseal  passes  down  almost  in  com 
tact  with  the  ligament,  and  gives  branches  to  the  con- 
tiguous parts  in  its  course.  It  generally  perforates  the  in- 
teroseous  ligament  near  the  wrist,  and  sends  off  many 
small  branches  to  the  back  of  the  wrist  and  hand,  which 
anastomose  with  the  small  branches  of  the  radial  and 
the  posterior  interosseal  arteries. 

The  Posterior  Interosseal  soon  gives  off  a recurrent  or 
anastomosing  branch,  and  then  proceeds  downwards  to- 
wards the  wrist,  sending  branches  in  its  course  to  the 
extensor  muscles  and  tendons. 

This  vessel  sometimes  divides  into  two  branches. 

The  ulnar  Artery. 

The  ulnar  artery  proceeds  among  the  muscles  ob- 
liquely downwards,  and  is  not  superficial  until  it  has  ar- 
rived within  three  or  four  inches  of  the  carpus:  it  then 
continues  towards  the  hand,  sending  off  very  small 
branches  in  its  progress.  It  passes  over  the  annular  liga- 


260 


Course  of  the  Ulnar  Artery , and 

ment  at  the  wrist,  and  winds  round  the  pisiform  bone: 
here  it  is  supported  by  a delicate  ligament,  which  seems 
to  lie  upon  it:  from  this  it  passes  upon  the  palm  of  the 
hand,  under  the  aponeurosis  palmaris,  and  over  the  ten- 
dons of  the  flexors  of  the  fingers.  When  thus  situated,  it 
forms,  in  perhaps  a majority  of  subjects,  an  arch  or  bow, 
called  arcus  sublimis,  which  extends  across  the  palm 
of  the  hand,  from  the  ulnar  towards  the  radial  edge,  and, 
after  sending  branches  to  the  fingers,  &c.,  from  its  con- 
vex side,  terminates  near  the  root  of  the  thumb,  by  an- 
astomosis with  that  important  branch  of  the  radial  ar- 
tery, which  passes  up  on  the  inside  of  the  thumb.  The 
arcus  sublimis  almost  always  sends  off  small  branches 
to  the  integuments,  &c.,  on  the  palm  of  the  hand.  It 
often  sends  off,  near  the  root  of  the  metacarpal  bone  of 
the  little  finger,  a branch  which  passes  between  the 
flexor  tendons  and  the  metacarpal  bones,  and  anasto- 
moses with  the  Arcus  Profundus.  It  then  generally  sends 
off  a branch  to  the  inner  or  ulnar  side  of  the  little  finger; 
and  afterwards  three  branches  in  succession,  which  pass 
from  its  convex  side  towards  the  angles  formed  by  the 
fingers.  These  are  called 

The  Digital  Arteries. 

When  they  have  arrived  near  to  the  heads  of  the  first 
phalanges  of  the  fingers,  each  of  these  arteries  divides 
into  two  branches,  one  of  which  passes  along  the  side  of 
one  of  the  fingers  to  its  extremity,  and  the  other  on  the 
opposite  side  of  the  next  finger:  and  in  this  way  they 
pass  on  the  sides  of  all  the  fingers,  except  the  inside  of 
the  little  finger  and  the  outside  of  the  index. 

These  branr  hes  of  the  digital  arteries  are  called  Digito 
Radial  and  Digito  Ulnar  arteries,  according  to  the  sides 
of  the  fingers  on  which  they  are  placed.  They  are  situa- 
ted on  the  angle,  if  it  may  be  so  termed,  which  is  formed 


Its  Ramifications  on  the  Hand  and  the  Fingers.  261 

by  the  anterior  and  lateral  surfaces  of  each  finger.  In 
their  course  from  the  basis  to  the  extremity  of  the  finger, 
they  send  off"  very  small  transverse  branches,  which  an- 
astomose with  each  other,  especially  near  the  other.  Some 
transverse  branches  are  observable  on  the  posterior  as 
well  as  the  anterior  surfaces.  Near  the  extremity  of  each 
finger,  beyond  the  insertion  of  the  flexor  tendon,  the  ex- 
tremities of  these  arteries  ramify  minutely.  Some  of 
these  small  branches  go  to  the  skin,  and  others  anasto- 
mose with  their  fellows  of  the  opposite  side.  Some  also 
go  to  the  back  of  the  fingers.* 

* The  distribution  of  the  radial  and  ulnar  arteries  in  the  hand,  is 
very  different  in  different  subjects. 

Upon  examining  a large  number  of  injected  preparations  in  Phi- 
ladelphia, it  was  found  that,  is  a very  small  majority  of  them,  the 
ulnar  artery  formed  an  arcus  sublimis,  whose  branches  extended  as 
far  as  the  ulnar  side  of  the  index,  and  sometimes  beyond  it. 

That,  in  near  a third  of  the  preparations,  the  ulnar  artery  ramified 
without  forming  an  arcus,  and  supplied  only  two  of  the  digital 
branches,  viz.  the  first  two  on  the  ulnar  side.  In  such  cases  the  radial 
artery  generally  made  up  the  deficiency  of  the  ulnar,  but  in  a few  in- 
stances the  interosseal  was  extended  on  the  palm  of  the  hand,  and 
supplied  the  radial  side  of  the  middle  finger  and  the  corresponding 
side  of  the  index. 

In  a few  instances  also  the  ulnar  artery  was  still  more  deficient, 
and  the  radial  was  proportionally  extended. 


262 


Bronchial  Artery . 


SECTION  III. 

Of  the  Branches  which  go  off  between  the  arch  and 
the  great  bifurcation  of  the  AORTA. 

PART  I. 

In  the  Cavity  of  the  Thorax. 

THE  aorta  sends  branches  to  the  Lungs , to  the  oeso- 
phagus, and  to  the  parietes  of  the  thorax. 


The  bronchial  Arteries 

Are  the  vessels  which  go  from  the  aorta  to  the  ramifica- 
tions of  the  trachea,  and  the  substance  of  the  lungs.  They 
are  not  large,  and  are  very  irregular  as  to  number  and  ori- 
gin. 

In  a majority  of  cases  the  right  lung  is  supplied,  in 
part,  by  a branch  from  the  first  aortic  intercostal  of  that 
side;  while  the  left  lung  receives  two  or  three  branches 
from  the  aorta  directly.  In  some  cases  a large  vessel 
arises  from  the  aorta,  which  divides  into  two  branches, 
one  of  which  goes  to  each  lung. 

The  bronchial  arteries  frequently  send  small  branch- 
es to  the  posterior  mediastinum,  the  pericardium,  &c. 

Injections  have  shown,  that  there  is  a direct  communi- 
cation between  these  vessels  and  the  branches  of  the 
pulmonary  artery. 

The  Oesophageal  Arteries 

Are  very  small  vessels,  which  generally  arise  from  the 
aorta,  but  sometimes  are  branches  of  the  bronchials  or 
intercostals  that  are  spent  upon  the  oesophagus.  They 
occur  in  succession,  and  sometimes  are  five  or  six  in 


intercostal  Arteries, 


263 


number.  They  also  send  twigs  to  the  contiguous  parts, 
and  the  lowermost  often  descend  to  the  stomach. 

The  Inferior  Intercostals 

Are  the  arteries  which  proceed  directly  from  the  aorta  . 
to  the  parietes  of  the  thorax.  Their  name  is  derived  from 
their  position  between  the  ribs.  They  are  ramified  on  the 
intercostal  muscles  and  ribs,  and  on  the  pleura  and  some 
of  the  contiguous  parts.  They  are  called  Inferior  or 
Aortic  Intercostals , to  distinguish  them  from  the  superior 
intercostals,  which  are  derived  from  the  subclavian  artery. 
Their  number  varies  from  ten  to  eight,  according  as  the 
superior  intercostals  are  more  or  less  numerous. 

They  originate  in  pairs  on  the  posterior  surface  of  the 
aorta.-  The  uppermost  of  them  pass  obliquely  upwards, 
and  the  lowermost  nearly  in  a horizontal  direction,  to 
the  lower  edges  of  those  ribs  to  which  they  are  appro- 
priated. They  meet  the  rib  near  its  tubercle,  or  place  of 
junction  with  the  transverse  process  of  the  vertebra,  and 
then  proceed  forward,  between  the  internal  and  external 
intercostal  muscles,  in  a superficial  but  large  groove, 
which  is  generally  to  be  found  on  the  interior  margin  of 
the  lowrer  surface  of  the  rib.*  There  is  necessarily  a differ- 
ence in  the  length  of  the  right  and  left  intercostals,  owing 
to  the  position  of  the  aorta,  which  is  rather  on  the  left  of 
the  spine.  In  consequence  of  this  circumstance,  the  oeso- 
phagus is  anterior  to,  and  also  in  contact  with  those  of 
the  right  side. 

They  generally  send  off  an  important  branch,  called 
the  Dorsal , which  arises  near  their  origin,  and,  passing 
backwards,  sends  ramifications  to  the  muscles  of  the 
back.  From  this  dorsal  branch  also  proceeds  a ramifica- 
tion, which  enters  the  spinal  cavity,  and  is  spent  upon  its 
membrane  and  upon  the  medulla  spinalis. 


* See  Vol.  I.  page.  83. 


264 


General  Account  of  the 

After  the  intercostals,  in  their  progress  forward, 
have  passed  beyond  the  middle  of  the  ribs,  they  send  off 
a branch,  which  generally  proceeds  very  near  to  the  upper 
side  of  the  lower  rib.  The  main  trunk  generally  leaves 
the  lower  edge  of  the  rib  when  it  has  arrived  within  one 
third  of  the  length  of  the  bone  from  its  anterior  extre- 
mity. It  then  generally  divides  into  several  branches, 
some  of  which  are  spent  upon  the  pleura,  and  others  on 
the  intercostal  and  the  contiguous  muscles. 

According  to  the  situation  of  the  different  intercostals, 
some  of  their  ramifications  communicate  with  those  of 
the  internal  and  external  mammaries,  of  the  phrenic,  the 
lumbar,  or  the  epigastric  arteries. 


PART  II. 

In  the  Cavity  of  the  Abdomen . 

The  AORTA  passes  into  the  cavity  of  the  abdomen 
between  the  crura  of  the  diaphragm,  as  has  been  already 
mentioned.  In  its  course  from  the  crura  to  its  great  bi- 
furcation, it  sends  off  one  pair  of  small  arteries,  called 
Phrenic , to  the  diaphragm.  Three  single  arteries,  the 
C CELIAC,  the  SUPERIOR,  and  the  INFERIOR 
mesenteric,  to  the  viscera  of  the  abdomen.  A pair  of 
large  arteries,  the  EMULGENTS,  to  the  kidneys,  with 
several  that  are  very  small  to  their  appendages;  as  the 
Spermatics,  Capsular , the  Ureteric , and  the  Adipose . In 
addition  to  these,  there  is  one  pair  of  small  arteries  that 
go  to  the  testicles,  or  to  the  ovaria  and  the  uterus,  and 
four  or  five  pair,  called  lumbar  arteries,  that  go  off 
laterally,  like  the  intercostals,  to  the  parietes  of  the  abdo- 
men, and  to  the  muscles,  &c.,  on  the  back,  which  are 
contiguous  to  them. 


Arteries  of  the  Abdomen . 


265 


The  phrenic  Arteries 

Are  ramified  on  the  concave  surface  of  the  diaphragm, 
and  are  almost  always  two  in  number;  they  are  denomi- 
nated right  and  left  from  their  position.  They  commonly 
originate  separately  from  the  aorta,  but  sometimes  they 
arise  in  a common  trunk  which  soon  divides.  In  some 
instances  they  are  derived  from  the  coeliac.  In  a few  cases 
the  aorta  furnishes  one,  and  the  cceliac  the  other.  Each  of 
the  phrenic  arteries  commonly  crosses  the  crus  of  the 
diaphragm  on  its  respective  side,  and  proceeding  laterally, 
in  a circular  direction,  often  ramifies  so  as  to  form  an 
internal  and  external  branch.  Each  of  them  generally 
sends  branches  to  the  cardia  or  oesophagus,  to  the  glandulse 
renales,  and  other  contiguous  parts. 

The  CCELIAC  Artery 

Is  the  first  great  branch  given  off  by  the  aorta  in  the 
abdomen,  and  is  distributed  almost  entirely  to  the  sto- 
mach, the  liver,  and  the  spleen.  It  projects  from  the  ante- 
rior part  of  the  aorta  so  as  to  form  a right  angle  with  it, 
and  is  of  course  nearly  horizontal  when  the  body  is  erect. 

The  main  trunk  of  this  great  artery  is  so  remarkably 
short,  that  it  has  been  compared  to  the  stump  of  a tree: 
for  at  the  distance  of  half  an  inch  from  its  origin,  it  ge- 
nerally divides  into  three  branches,  which  pass  to  the 
stomach,  the  liver,  and  the  spleen,  and  are,  therefore,  de- 
nominated the  gastric  or  coronary,  the  HEPATIC 
and  the  SP  LENIC  arteries. 

The  first  mentioned  branch  may  be  called 

2 L 


VOL.  II. 


266 


Distribution  of 


The  SUPERIOR  CORONARY  Or  GASTRIC  ARTERY, 

To  distinguish  it  from  other  branches,  soon  to  be  describ- 
ed. It  is  commonly  in  the  center  of  the  three  great  rami- 
fications of  the  cceliac,  and  is  also  the  smallest  of  them.  It 
proceeds  from  its  origin  to  the  upper  orifice  of  the  stomach 
or  cardia,  and  continues  thence  along  the  lesser  curvature 
of  that  viscus,  until  it  approaches  near  to  the  pylorus.  In 
this  course  it  sends  branches  to  the  oesophagus,  which 
frequently  inosculate  with  the  oesophageal  arteries.  It  also 
furnishes  branches  to  the  cardia,  which  partially  surround 
it;  and  on  this  account,  the  artery  has  been  called  Co- 
ronary. Some  of  these  last  mentioned  branches  are  often 
continued  on  the  great  extremity  of  the  stomach,  and 
anastomose  with  those  ramifications  of  the  splenic  artery, 
called  Vasa  Brevia. 

It  continues  on  the  lesser  curvature  between  the  laminae 
of  the  small  omentum,  and  sends  off  successively  branch- 
es which  pass  between  the  peritoneal  and  muscular  coats, 
and  are  distributed  to  the  anterior  and  posterior  surfaces 
of  the  stomach,  communicating  with  the  branches  of  the 
inferior  gastric  arteries,  soon  to  be  described.* 


The  HEPATIC  Artery 

Proceeds  from  the  great  ramification  of  the  coeliac  to  the 
transverse  fissure  of  the  liver  called  the  Porta , in  which 
it  generally  divides  into  two  branches.  In  this  course  it 
very  frequently  sends  off  an  artery  to  the  pylorus,  which 
ramifies  about  the  small  extremity  of  the  stomach,  and 
often  inosculates  with  some  of  the  branches  of  the  supe- 
rior coronary.  This  branch  is  called  the  Pylorica , and 
sometimes  it  arises  from  the  artery'  next  to  be  mentioned. 

* This  artery  sometimes  sends  a branch  to  the  liver.  When  this 
is  the  case,  it  is  always  very  large. 


the  Cceliac  Artery. 


267 


The  GASTRICA  INFERIOR,  DEXTRA, 

Which  also  generally  originates  from  the  main  trunk 
of  the  hepatic,  but  sometimes  from  one  of  its  branches.  It 
is  an  artery  of  considerable  size,  which  proceeds  along  the 
great  curvature  of  the  stomach,  from  the  pylorus  towards 
the  great  extremity,  between  the  laminae  of  the  anterior 
portion  of  the  omentum,  and  distributes  its  ramifications 
to  both  sides  of  the  stomach,  and  also  to  the  Omentum.  In 
its  progress  from  the  hepatic  artery  to  the  stomach,  it 
sends  off  branches  to  the  Duodenum , and  to  the  right  end 
of  the  Pancreas. 

The  two  great  branches  into  which  the  HEPATIC . 
arterv  divides  are  denominated  right  and  left,  from 
the  lobes  of  the  viscus,  to  which  they  are  respectively 
appropriated.  The  right  branch  is  the  largest.  Before  it 
penetrates  the  substance  of  the  liver,  it  sends  off  a branch 
to  the  gall  bladder,  called  the  Cystic  Artery. 

The  branches  of  the  hepatic  artery  ramify  very  minutely 
in  the  liver,  as  has  been  stated  in  the  account  of  that  organ. 

The  last  great  branch  of  the  cceliac  is 

The  SPLENIC  Artery , 

Which  is  generally  supposed  to  be  larger  than  the  hepatic 
in  adults,  although  it  is  less  in  children.  It  proceeds  in  a 
transverse  direction  from  its  origin  to  the  spleen:  its 
course  is  not  straight,  but  meandering  or  serpentine.  It 
is  situated  behind  and  above  the  pancreas,  and  passes 
along  the  groove  in  the  upper  edge  of  that  viscus.  In  its 
progress,  it  sends  off’  many  small  branches,  and  one  that 
is  of  considerable  size,  to  the  Pancreas.  It  also  sends 
one  branch  to  the  left  extremity  of  the  stomach,  which 
arises  commonly  from  the  main  trunk,  but  sometimes 
from  the  ramifications,  which  are  soon  to  be  mentioned. 
This  branch,  which  is  called 


268 


Distribution  of  the  Splenic 


The  CASTRICA  INFERIOR  SINISTRA, 

Is  sometimes,  but  not  often,  very  large:  Its  course  is 
from  left  to  right.  It  is  situated  between  the  laminae  of  the 
anterior  portion  of  the  omentum.  It  sends  some  small 
branches  to  the  omentum,  and  others  which  are  larger 
and  more  numerous,  to  both  sides  of  the  stomach.  Some 
of  these  last  mentioned  anastomose  with  the  ramifications 
of  the  gastrica  dextra,  which  come  from  the  hepatic. 

When  the  SPLENIC  artery  approaches  near  to  the 
spleen,  it  divides  into  four,  five,  or  six  branches,  each  of 
which  penetrates  into  that  viscus  by  a distinct  foramen, 
and  then  ramifies  in  the  manner  described  in  the  account 
of  the  structure  of  the  spleen.* 

Either  from  the  splenic  artery,  or  from  these  ramifica- 
tions, four  or  five  branches  pass  to  the  large  extremity  of 
the  stomach,  and  ramify  there,  communicating  with  the 
vessels  already  described. — These  arteries  have  received 
great  attention  from  physiologists,  and  are  denominated 
Vasa  Brevia, 

The  SUPERIOR  MESENTERIC, 

Which  is  the  second  great  branch  given  off  in  the  abdo- 
men by  the  aorta,  is  not  very  different  in  size  from  the 
coeliac,  and  originates  about  half  an  inch  below  it.  It  is 
distributed  to  the  small  intestines;  to  that  portion  of  the 
great  intestine,  which  is  situated  on  the  right  side  of  the 
abdomen;  and  to  the  arch  of  the  colon.  From  its  origin 
it  proceeds  downwards,  under  the  pancreas,  and  over  the- 
lower  portion  of  the  duodenum,  to  the  commencement 
of  the  mesentery.  When  it  has  arrived  between  the  la- 

* It  frequently  happens  that  the  splenic  artery  divides  only  into 
two  or  three  branches,  and  they  subdivide  so  as  to  form  five  or  six, 
which  penetrate  the  spleen, 


and  the  Superior  Mesenteric  Arteries.  269 

minae  of  that  membrane,  it  descends  in  a direction  which 
corresponds  with  that  of  the  root  of  the  mesentery,*  and 
forms  a gentle  curve,  with  its  convexity  directed  towards 
the  intestines.  It  necessarily  diminishes  as  it  descends, 
and  generally  terminates  by  anastomosing  with  one  of  its 
own  branches.-— This  great  artery  sends  off  some  very 
small  ramifications  to  the  pancreas  and  the  duodenum, 
while  it  is  in  their  vicinity.  It  also  sends  two  or  three 
branches  to  the  transverse  part  of  the  colon,  to  the  right 
portion  of  the  colon,  to  the  beginning  of  the  great  intes- 
tine, and  the  contiguous  portion  of  the  ileon.  These 
branches  are  commonly  termed  the  colica  media,  co- 
l i c a dextea,  and  ileo  conic  a.  From  the  convex  side 
of  the  curve,  the  SUPERIOR  MESENTERIC  sends  off 
the  important  branches  which  pass  between  the  laminae 
of  the  mesentery,  and  supply  the  Small  Intestines.  These 
branches  are  numerous,  and  many  of  their  ramifications 
anastomose  with  each  other  so  as  to  form  arches.  From 
these  arches  go  off  other  branches,  which  anastomose 
again  with  some  of  similar  origin;  and  this  process  is  re- 
peated successively  several  times,  so  that  a net-work  of 
bloodvessels  seems  to  be  formed  on  the  mesentery.  From 
the  mesentery  the  small  ramifications  are  continued  in 
great  numbers  to  the  intestines.  Some  of  them  anasto- 
mose with  each  other  on  the  coats  of  the  intestine;  but 
an  immense  number  of  minute  arteries  are  continued  to 
the  villous  coat,  so  that,  when  they  are  successfully  in- 
jected, the  surface  of  that  coat  appears  uniformly  co- 
loured by  the  injection. j- 

* See  Vol.  II.  page  1 14. 

t See  the  account  of  the  termination  of  these  arteries,  at  page  104 
of  this  volume. 


270  Distribution  of  the  Inferior  Mesenteric. 

The  INFERIOR  MESENTERIC  Artery 

Does  not  go  off  from  the  aorta  next  in  order  after  the 
superior  mesenteric,  but  succeeds  it  immediately  on  the 
intestines,  and  continues  the  arterial  ramifications  to  the 
left  portion  of  the  colon , to  which  the  branches  of  the 
superior  mesenteric  do  not  extend. 

This  artery  arises  between  the  origin  of  the  emul- 
gents,  and  the  great  bifurcation  of  the  aorta,  and  pro- 
ceeds downwards,  inclining  to  the  left,  but  keeping  near 
to  the  aorta.  There  are  generally  three  branches  distri- 
buted to  the  left  portion  of  the  colon,  which  arise  from 
this  artery,  either  separately,  or  by  a common  trunk 
which  soon  divides.  It  frequently  happens,  that  one  of 
these  arteries  arises  separately,  and  two  by  a common 
trunk.  These  are  called  the  left  colic  arteries;  and 
are  also  sometimes  denominated,  from  their  position, 

SUPERIOR,  MIDDLE,  and  INFERIOR.  The  SUPERIOR 

generally  anastomoses  with  that  branch  of  the  superior 
mesenteric,  which  is  called  colica  media,  and  forms 
a remarkable  arch,  called  the  Great  Mesocolic  Arch. 
The  ramifications  of  the  other  branches  frequently  anas- 
tomose with  each  other,  and  are  finally  spent  upon  the 
left  portion  of  the  colon. 

The  main  trunk,  diminished  by  sending  off  these 
branches,  but  still  of  considerable  size,  runs  downwards 
on  the  posterior  part  of  the  intestine  rectum,  between 
that  intestine  and  the  sacrum,  where  it  often  divides 
into  two  branches,  which  continue  near  to  the  termina- 
tion of  the  rectum.  From  them  proceed  many  ramifica- 
tions that  are  spent  upon  the  rectum.  Some  of  these  ra- 
mifications anastomose  with  each  other,  and  others  with 
the  ramifications  of  the  hemorrhoidal  artery,  soon  to  be 
mentioned. 


Arteries  of  the  Kidneys  and  Renal  Glands.  271 


The  EMULGENT  or  RENAL  Arteries 

Are  the  large  vessels  which  pass  from  the  aorta  to  the 
kidneys.  They  arise  between  the  superior  and  inferior 
mesenteries,  one  on  each  side;  and  proceed  in  a direc- 
tion which  is  nearly  rectangular  to  the  aorta.  The  right 
emulgent  artery  is  necessarily  longer  than  the  left,  and  it 
generally  passes  behind  the  vena  cava.  When  they  ap- 
proach near  the  concave  edges  of  the  kidneys,  each 
emulgent  commonly  divides  into  three  or  four  branches, 
which  pass  into  the  fissure  of  that  organ,  and  ramify  in 
the  manner  described  in  the  account  of  it.  Sometimes 
two  arteries  proceed  from  the  aorta  to  the  kidney:  but 
this  is  not  a frequent  occurrence. 

The  Capsular  Arteries 

Are  the  small  vessels  which  pass  to  the  glandular  re- 
nales.  There  are  almost  always  several  of  them  appro- 
priated to  each  gland.  They  often  arise  on  each  side 
from  the  coeliac  artery,  the  aorta,  and  the  emulgent. 


The  Adipose  Arteries 

Supply  the  adipose  substance  surrounding  the  kidneys.—* 
There  are  several  of  them  on  each  side,  and,  like  the  last 
mentioned  arteries,  they  are  very  small,  and  arise  from 
several  sources  as  well  as  the  aorta. 

The  testicles  and  ovaria  are  supplied  by  the 

Spermatic  Arteries , 

Which  are  very  remarkable  for  their  great  length  and 
small  diameter.  In  a majority  of  cases  these  vessels  arise 
from  the  anterior  surface  of  the  aorta,  a little  below  the 


272 


Spermatic  Arteries. 

emulgents:  but  it  often  happens  that  the  left  spermatic 
arises  from  the  emulgent  on  that  side.  They  also  some- 
times arise  from  other  neighbouring  arteries.  It  has  been 
observed  when  they  arise  from  the  aorta,  that  the  origin 
of  one  of  them  is  generally  higher  than  that  of  the  other. 

They  pass  downwards,  so  as  to  form  an  acute  angle 
with  the  aorta,  and  proceed  behind  the  peritoneum,  and 
before  the  psoas  muscle  and  ureter.  While  this  artery  is 
in  contact  with  the  psoas  muscle,  it  meets  with  the  rami- 
fications of  the  spermatic  vein , and,  in  its  progress  to  the 
abdominal  ring,  also  joins  the  spermatic  cord.  In  this 
course  it  sends  off  some  very  small  twigs  to  the  conti- 
guous parts,  and  others  that  anastomose  with  similar 
ramifications  from  the  mesenteric,  epigastric,  &c.  Before 
it  arrives  at  the  testicle,  it  divides  into  several  branches, 
two  of  which  generally  go  to  the  epididymis,  and  the 
others  penetrate  the  upper  and  back  part  of  the  tunica 
albuginea. 

The  Spermatic  Arteries  in  the  Female , 

Instead  of  passing  to  the  abdominal  ring,  proceed  between 
the  laminae  of  the  broad  ligaments,  and  send  branches  to 
the  ovaria,  which,  in  some  cases,  may  be  traced  to  the 
vesicles.  They  also  send  branches  to  the  fallopian  tubes 
and  uterus,  and  to  the  round  ligaments.  Those  which  are 
on  the  opposite  sides  of  the  uterus,  anastomose  with  each 
other  and  with  the  branches  of  the  hypogastric  arteries. 

The  lumbar  regions  are  supplied  with  arteries,  which 
originate,  like  the  intercostals,  from  the  posterior  part  of 
the  aorta  between  the  thorax  and  pelvis.  There  are  four 
or  five  of  these  vessels  on  each  side,  and  they  are  deno 
minated 


Arteries  above  and  at  the  bifurcation  of  the  Aorta . 273 


The  Lumbar  Arteries: 

They  pass  between  the  spine  and  the  psoas  muscles,  and 
send  branches  to  the  spinal  cavity,  to  the  muscles  of  the 
lumbar  regions,  and  the  abdominal  muscles.  They  anasto- 
mose with  the  internal  mammary,  the  epigastric,  the  cir- 
cumflex of  the  ileum,  &c. 

A small  artery  passes  off  singly  from  the  posterior  part 
of  the  aorta  at  its  bifurcation,  which  is  called 

The  Middle  Sacral  Artery. 

It  proceeds  down  the  middle  of  the  sacrum  to  the  os 
coccygis,  and  sends  off  lateral  branches,  which  are  spent 
upon  the  contiguous  parts,  and  inosculate  with  the  arterise 
sacrse  laterales. 


SECTION  IV. 

Of  the  Arteries  which  originate  at  and  below  the  Great 
Bifurcation  of  the  Aorta. 

The  PRIMITIVE  ILIACS 

Form  an  acute  angle  with  each  other.  They  proceed 
downwards  behind  the  peritoneum,  very  near  the  margin 
of  the  pelvis,  without  sending  off  any  branch  of  impor- 
tance. At  the  junction  of  the  sacrum  with  the  ossa  ilea, 
they  divide  into  two  great  branches:  the  INTERNAL 
ILIAC , or  HYPOGASTRIC , which  descends  into  the 
pelvis;  and  the  EXTERNAL  ILIAC , which  passes 
under  the  qrural  arch  to  the  lower  extremity. 

Vol.  If.  2 M 


274  General  Account  of  the  Internal  Iliac. 

The  INTERNAL  ILIAC , or  HYPOGASTRIC , 

Is  distributed,  in  part,  to  the  viscera  of  the  pelvis  and  the 
organs  of  generation,  and  also  to  the  large  muscles  ex- 
terior to  the  pelvis:  it  is,  therefore,  very  large,  although 
not  quite  equal  to  the  EXTERNAL  ILIAC. 

It  has  already  been  mentioned,  that  in  the  foetal  state, 
this  vessel  appeared  to  continue  in  a curved  direction 
from  its  origin  to  the  lower  part  of  the  side  of  the  bladder, 
and  from  thence  to  the  umbilicus,  under  the  denomination 
of  the  Umbilical  Artery.  From  the  convex  side  of  this 
curve  the  different  branches  of  the  internal  iliac  go  off.  In 
the  foetal  state  they  are  very  small  in  proportion  to  the 
umbilical  artery;  but  as  the  artery  becomes  ligamentous, 
these  branches  increase  in  size. 

In  the  adult,  the  arrangement  of  these  vessels  is  very 
different.  The  INTERNAL  ILIAC  generally  divides 
into  two  great  branches:  the  gluteal,  which  passes 
through  the  sacro  sciatic  notch,  and  ramifies  on  the  ex- 
terior and  upper  part  of  the  os  ileum;  and  the  ischiatic, 
which  passes  downwards  on  the  outside  of  the  tuberosity 
of  the  ischium. 

The  first  of  these  large  ramifications  passes  out  of  the 
pelvis  above  the  pyriform  muscle,  and  the  last  of  them 
below  it.  Several  smaller  arteries  arise  from  these  branches 
near  their  origin,  or  from  the  main  trunk  of  the  internal 
iliac,  which  are  distributed  to  the  different  parts  of  the 
pelvis;  and  one  important  branch  of  the  ischiatic,  called 
the  pudic,  proceeds  downward  on  the  inside  of  the  tu- 
berosity of  the  ischium. 

The  first  of  the  smaller  branches  which  the  internal 
iliac  commonly  sends  off,  is  called  the 


Smaller  Branches  of  the  Internal  Iliac. 


275 


Ileo  Lumbalis: 

It  sometimes  arises  from  the  gluteal  artery,  and  some- 
times from  the  main  trunk  of  the  internal  iliac.  It  passes 
outwards  under  the  psoas  muscle,  and  suddenly  divides 
into  two  branches.  One  of  them  proceeds  upwards,  and 
is  distributed  in  the  lumbar  region,  while  the  other  rami- 
fies on  the  iliacus  internus  muscle,  and  is  spent  on  the 
contiguous  parts. 

There  are  also  two  or  three  small  arteries  called 
Arteries  Sacra  Later  ales, 

Which  sometimes  arise  singly,  and  sometimes  in  com- 
mon, from  the  great  trunk.  They  also  occasionally  origi- 
nate from  the  gluteal  artery.  These  vessels  enter  the  an- 
terior foramina  of  the  os  sacrum,  to  be  distributed  on  the 
cauda  equina  and  the  membranes  which  invest  it.  Some 
of  their  ramifications  anastomose  with  branches  of  the 
sacra  media  and  other  contiguous  arteries. 

On  the  anterior  side  of  the  internal  iliac,  near  the  origin 
of  the  above  mentioned  vessels,  a ligament  which  was 
originally  the  umbilical  artery,  goes  off  to  the  side  of 
the  bladder,  and  continues  from  thence  to  the  umbilicus. 
Sometimes  it  continues  pervious  for  a short  distance,  and 
then  small  branches  pass  from  it  to  the  bladder. 

In  the  female  it  also  sends  small  branches  to  the  uterus 
and  vagina. 

In  addition  to  these  Vesical  Arteries  derived  from  the 
umbilicals,  there  are  other  branches  distributed  to  the 
bladder,  which  arise  very  differently,  in  different  subjects, 
from  branches  which  are  soon  to  be  described,  as  the  he- 
morrhoidal, pudic,  &c. 

From  the  anterior  side  of  the  internal  iliac,  or  from  one 
of  its  great  branches,  an  artery  often  arises  which  passes 


276  Smaller  Branches  of  the  Internal  Iliac . 

out  of  the  pelvis  through  the  aperture  in  the  margin  of 
the  ligamentous  membrane  which  closes  the  foramen 
'thyroideum  of  the  os  innominatum;  this  is  called  the 

Obturator  Artery.  * 

This  vessel,  while  it  is  in  the  pelvis,  often  sends  small 
branches  to  the  bladder  and  its  appendages,  and  to  the 
obturator  internus  muscle.  After  it  passes  out  of  the  pelvis, 
it  frequently  divides  into  branches;  some  of  which  are 
spent  on  the  obturator  externus,  and  the  contiguous 
muscles,  and  others  go  to  the  hip  joint.  The  origin  of 
this  artery  is  variable.  Most  commonly  it  arises  from  the 
internal  iliac,  but  often  from  the  ischiatic,  and  sometimes 
from  the  gluteal.  In  some  instances  it  originates  in  a way 
that  is  particularly  interesting  when  the  operation  for 
crural  hernia  is  to  be  performed,  viz.  from  the  epigastric 
artery,  soon  to  be  described:  for  in  this  case  the  obturator 
artery  sometimes  nearly  surrounds  the  neck  of  the  hernial 
sac.* 

A small  artery  passes  from  the  internal  iliac  or  one  of 
its  branches,  to  the  rectum,  which  is  called  the 

Middle  Hemorrhoidal, 

From  its  situation  between  the  branches  which  are  sent 
to  that  intestine  from  the  inferior  mesenteric,  and  those 
which  go  to  it  from  the  pudic.  This  artery  is  spent  upon 
that  part  of  the  rectum,  which  is  above  and  in  contact 
with  the  sphincter.  It  sends  branches  to  the  prostate  and 
vesiculae  seminales  in  males,  and  the  vagina  and  bladder 
in  females. 

In  females  there  is  a peculiar  artery, 

* See  Astley  Cooper’s  great  work  on  Hernia,  Vol.  I. 

There  is  reason  to  believe  that  this  position  of  the  artery  occurs 
more  frequently  than  has  been  supposed. 


Larger  Branches  of  the  Internal  Iliac. 


277 


The  Uterine , 

Which  originates  either  from  the  internal  iliac,  near  the 
origin  of  the  ischiatic,  or  from  one  of  its  branches.  It 
passes  between  the  laminae  of  the  broad  ligaments  to  the 
cervix  uteri,  and  penetrates  the  texture  of  that  organ. 
The  size  of  this  vessel  varies  with  the  varying  size  of  the 
uterus. 


The  gluteal  or  posterior  iliac  Artery , ’ 

One  of  the  two  great  branches  of  the  internal  iliac,  pro- 
ceeds exteriorly  through  the  sciatic  notch  above  the  pyri- 
form muscle,  very  near  the  edge  of  the  bone.  On  the  out- 
side of  the  ilium  it  generally  divides  into  two  branches, 
one  of  which  ramifies  between  the  gluteus  inedius  and 
minimus,  and  the  other  between  the  medius  and  maximus. 
It  is  principally  spent  upon  these  muscles,  and  sends 
branches  to  the  contiguous  parts. 


The  ischiatic  Artery , 

The  other  great  branch  of  the  internal  iliac,  passes  through 
the  sciatic  notch  below  the  pyriform  muscle,  and  proceeds 
downwards,  between  the  great  trochanter  of  the  os  femoris 
and  the  tuberosity  of  the  ischium,  under  the  gluteus 
maximus  muscle.  Soon  after  its  origin,  it  commonly  sends 
off  a considerable  branch,  the  Arteria  Pudica,  which  also 
passes  downwards:  it  then  continues  its  course  as  above 
mentioned,  and  its  principal  branches  are  distributed  to 
the  gluteus  maximus  and  the  muscles  of  the  upper  and 
back  part  of  the  thigh,  while  its  smaller  branches  go  to 
the  os  sacrum  and  coccyx,  and  the  contiguous  small 
muscles. 


278 


Pudic  Artery. 


The  PUDICA  INTERNA,  » 

As  has  been  just  mentioned,  is  often  a branch  of  the 
ischiatin  artery,  but  sometimes  originates  immediately 
from  the  internal  iliac.  It  proceeds  downwards  and  in- 
wards, diverging  from  the  ischiatic,  and  passing  between 
the  two  sacro  sciatic  ligaments  to  the  interior  side  of  the 
tuberosity  of  the  ischium,  whence  it  continues  on  the 
inside  of  the  crus  of  the  os  ischium  and  pubis  until  it 
approaches  the  symphysis,  when  it  generally  divides  into 
three  branches,  which  are  spent  upon  the  organs  of  gene- 
ration, from  which  circumstance  the  name  of  this  artery 
» is  derived. 

One  or  more  branches  from  it  also  pass  to  the  lower 
part  of  the  rectum  and  sphincter  ani,  and  are  called  the 
Lower  Hcemorrhoidal  Arteries. 

In  its  course  it  sends  off  many  small  branches  to  the 
contiguous  parts;  one  of  which,  called  the  Perineal , leaves 
it  near  the  transversus  perinei  muscle,  and  passes  between 
that  muscle  and  the  skin,  and  between  the  bulb  of  the 
urethra  and  the  crus  of  the  penis,  to  the  scrotum. 

When  the  pudic  has  arrived  near  the  bulb  of  the 
urethra  it  sends  a branch  into  it,  which  is  continued  into 
the  corpus  spongiosum  urethrae,  and  ramifies  there  mi- 
nutely. 

At  the  symphysis  of  the  pubis,  it  sends  off  a second 
branch,  which  passes  to  the  back  of  each  crus,  and,  pro- 
ceeding along  it,  parallel  to  its  fellow,  terminates  in  the 
glans  penis:  in  this  course  it  sends  branches  to  the  elastic 
coat,  to  the  integuments,  and  to  the  prepuce.  This  vessel 
is  called  the  Arteria  Dorsalis. 

The  main  trunk  of  the  pudic  artery  then  penetrates  the 
corpus  cavernosum,  and  proceeds  through  it  in  a straight 
direction.  Its  ramifications  appear  to  be  distributed 
through  the  internal  structure  of  the  corpus  cavernosut?!, 


External  Iliac.  Branches  of  the  External  Iliac.  279 

and  some  of  them  extend  through  the  septum  to  the  other 
side,  while  others  pass  to  the  corpus  spongiosum  urethras. 

The  EXTERNAL  ILIAC, 

The  great  artery  of  the  lower  extremity,  appears  soon 
after  birth,  like  a continuation  of  the  primitive  iliac,  and 
proceeds  along  the  brim  of  the  pelvis  behind  the  peri- 
toneum, to  Poupart’s  ligament  or  the  crural  arch,  under 
which  it  passes. 

The  psoas  muscle  is  at  first  in  contact  with  it  on  the 
outside,  and  the  internal  iliac  vein  on  the  inside.  As  it 
passes  under  Poupart’s  ligament,  it  is  immediately  ante- 
rior to  the  psoas  and  iliacus  internus  muscles  where  they 
are  united,  and  the  crural  nerve  is  exterior  to  it.  Before 
it  arrives  at  the  lower  edge  of  Poupart’s  ligament,  it  sends 
off 


The  Epigastric  Artery , 

Which  arises  on  its  internal  side,  and  proceeds  down- 
wards and  inwards  about  half  an  inch,  then  it  turns  up- 
wards and  inwards,  and  continues  in  that  direction  for 
a small  distance,  after  which  its  course  is  less  oblique.  It 
passes  between  the  peritoneum  and  the  abdominal  mus- 
cles, behind  the  spermatic  cord,  and  the  round  ligament 
in  females. 

It  generally  changes  its  oblique  direction  after  passing 
about  two  inches,  and  then  proceeds  in  contact  with  the 
rectus,  and  very  near  its  external  edge.  Its  ramifications 
are  expended  upon  the  anterior  parietes  of  the  abdomen; 
and,  after  it  has  arrived  as  high  as  the  umbilicus,  it  com- 
. monly  divides  into  branches,  which  often  inosculate  with 
the  ramifications  of  the  internal  mammary.* 

* Several  respectable  surgeons  have  been  taught  by  experience, 
that  when  the  abdomen  is  distended  by  ascites,  the  position  of  the 


280  General  Account  of  the  Femoral  Artery. 

An  artery,  which  is  rather  smaller  than  the  epigastric, 
arises  nearly  opposite  to  it,  but  rather  lower,  from  the 
external  side  of  the  external  iliac.  It  is  called 

The  Circumflex  Artery  of  the  Os  Ilium, 

And  proceeds  upwards  and  outwards  to  the  upper  margin 
of  the  os  ilium,  along  which  it  continues  very  near  to  the 
spine.  It  is  distributed  principally  to  the  abdominal  mus- 
cles, to  the  iliacus  internus  and  the  psoas,  and  the  parts 
contiguous. 

The  artery  of  the  lower  extremity,  after  passing  under 
Poupart’s  ligament,  takes  the  name  of 

FEMORAL  Artery , 

And  proceeds  downwards  in  a direction  so  spiral,  that 
although  it  is  in  front  at  the  upper  part  of  the  thigh,  it  is 
completely  behind  at  the  lower  part.  It  sends  branches  to 
the  muscles  of  the  thigh,  as  the  aorta  does  to  the  viscera 
of  the  abdomen,  viz.  by  a few  large  vessels  which  extend 
and  ramify  to  a great  distance  among  them. 

The  situation  of  the  adductor  muscles,  and  their  attach- 
ment to  the  os  femoris,  is  such,  that  the  artery  in  this 
course  must  necessarily  perforate  their  common  tendon, 
which  it  does  at  the  distance  of  one  third  of  the  length  of 
the  bone  from  its  lower  end.  The  aperture  in  this  tendon 
corresponds  precisely  with  the  general  course  of  the 
artery;  and  before  the  artery  enters  this  perforation,  it 
is  on  the  internal  side  of  the  bone;  after  it  has  passed  the 
perforation,  it  is  on  the  posterior  side  of  it.  After  passing 
through  the  tendon  of  the  adductors,  it  is  denominated 

epigastric  artery  is  so  much  altered,  that  it  will  sometimes  be  found 
in  the  middle  of  the  oblique  line,  which  extends  from  the  umbilicus 
to  the  superior  anterior  spine  of  the  ileum. 


Profunda  and  Circumflex  branches  of  the  Femoral.  281 

The  Popliteal  Artery , and  it  retains  this  name  until  it 
divides. 

It  then  proceeds  downwards,  being  very  near  the  bone, 
and  between  the  tendons  of  the  flexors  of  the  leg,  covered 
by  the  great  nerve  of  the  lower  extremity,  and  very  often 
also  by  the  vein.  After  crossing  the  articulation  of  the 
knee,  when  it  is  between  the  heads  of  the  gastroc  nemii 
muscles,  at  the  lower  edge  of  the  popliteus  muscle,  it 
divides  into  the  anterior  tibial  and  the  common  trunk  of 
the  peroneal  and  posterior  tibial  arteries. 

The  FEMORAL  artery,  soon  after  emerging  from 
Poupart’s  ligament,  sends  off  very  small  branches  to  the 
inguinal  glands,  and  other  contiguous  parts.  It  also  sends 
off-  the 

External  Pudics, 

Which  are  two  or  three  small  arteries  that  are  generally 
spent  upon  the  Scrotum  in  males  and  the  Labia  Pudendi 
in  females. 

About  two  inches  below  Poupart’s  ligament,  the  great 
branch  which  has  been  called  the  muscular  artery  of  the 
thigh,  leaves  it.  This  vessel  is  commonly  denominated 


ARTERIA  PROFUNDA. 

It  arises  from  the  back  part  of  the  trunk  of  the  femoral, 
and  passes  downwards  and  backwards,  in  a way  that  has 
been  compared  to  the  separation  of  the  internal  iliac  from 
the  external.  Very  soon  after  its  origin,  it  sends  off  two 
branches,  which  proceed,  one  on  the  internal,  and  the 
other  on  the  external  side  of  the  thigh,  and  are  called  the 
circumflexa  interna  and  externa.  It  then  passes  down- 
wards behind  the  trunk  of  the  femoral,  and  sometimes 
Vol.  II.  2 N 


282  Branches  of  the  Profunda  and  the  Femoral. 

very  near  it,  on  the  adductor  muscles,  and  finally  divides 
into  branches,  which  are  called  the  Perforating. 

The  External  Circumflex 

Sometimes  arises  from  the  femoral,  but  most  commonly 
is  a branch  of  the  profunda,  as  above  stated.  It  passes 
under  the  rectus  and  tensor  vaginae  femoris  towards  the 
great  trochanter,  and  generally  divides  into  two  branches, 
one  of  which  continues  in  the  transverse  direction,  and 
sends  branches  to  the  upper  and  back  part  of  the  thigh, 
and  the  parts  contiguous  to  the  joint;  while  the  other  de- 
scends in  the  course  of  the  rectus  femoris  muscle,  and 
some  of  its  ramifications  extend  near  to  the  outside  of  the 
knee. 

The  Internal  Circumflex 

Is  often  smaller  than  the  other.  It  generally  passes  be- 
tween the  psoas  and  the  pectineus  muscles,  and  continues 
round  the  thigh  towards  the  lesser  trochanter.  Its  ramifi- 
cations are  expended  on  the  upper  portions  of  the  adduc- 
tor muscles  and  the  muscular  parts  contiguous  to  the 
lesser  trochanter.  It  also  sends  branches  to  the  articulation. 

The  Perforating  Arteries 

Are  two  or  three  ramifications  of  the  profunda,  which 
pass  through  the  adductor  muscles,  and  are  expended 
upon  the  flexor  muscles  on  the  back  of  the  thigh.  Some 
of  the  terminating  branches  of  the  profunda  itself  are  also 
called  perforating  arteries. 

The  next  branch  of  importance  which  is  sent  off"  by  the 
FEMORAL  artery,  leaves  it  before  it  enters  the  aperture 
in  the  tendon  of  the  adductors,  and  is  called 


Branches  about  the  Ham. 


283 


The  Anastomotic  Artery. 

This  vessel  soon  inclines  downwards.  Its  ramifications 
extend  into  the  vastus  interims  muscle;  some  of  them 
follow  the  tendon  of  the  adductors,  and  ramify  about  the 
internal  condyle. 

Several  small  branches  go  off  from  the  great  artery 
soon  after  it  passes  through  the  tendon  of  the  adductors, 
which  are  distributed  to  the  contiguous  muscles.  Some 
of  them  are  also  called 

Perforating  Arteries. 

Among  them  is  the  principal  medullary  artery  of  the  os 
femoris. 

In  the  ham,  the  great  vessel  there  called 


POPLITEAL , 

generally  sends  off  several  small  branches.  Two  of  them 
go  off  on  the  inside,  one  above  and  the  other  below  the 
knee;  and  two  on  the  outside  in  the  same  manner.  They 
are  named,  from  their  situation,  The  Superior  and  Infe- 
rior Internal,  and  The  Superior  and  Inferior  External 
Articulary  Arteries. 

The  Superior  Internal  artery  perforates  the  tendon  of 
the  adductors  above  the  internal  condyle,  and  ramifies 
minutely  on  the  inner  side  of  the  joint. 

The  Superior  External  artery  passes  through  the  lower 
portion  of  the  biceps  above  the  external  condyle,  and  ra- 
mifies minutely  on  the  outer  side  of  the  joint.  Its  superior 
ramifications  anastomose  with  those  of  the  descending 
branch  of  the  external  circumflex,  while  its  inferior  rami- 
fications communicate  with  those  of  the  corresponding 
artery  below. 


284 


Arteries  of  the  Leg. 

The  two  inferior  arteries  originate  nearly  opposite  to 
the  middle  of  the  joint,  and  pass  downwards. 

The  Inferior  Internal  artery  passes  under  the  internal 
head  of  the  gastroc  nemius  muscle,  on  the  posterior  and 
internal  side  of  the  head  of  the  tibia.  Its  ramifications 
communicate  with  those  of  the  corresponding  artery 
above  and  of  the  tibialis  antica.  Below  they  also  extend 
to  the  interior  of  the  joint. 

The  Inferior  External  artery  passes  under  the  external 
head  of  the  gastroc  nemius  and  the  plantaris  muscle,  and 
continues  under  the  external  lateral,  and  the  capsular  liga- 
ment. It  is  distributed  on  the  external  and  inferior  part 
of  the  articulation,  and  sends  also  some  branches  to  the 
interior  of  the  joint. 

There  is  frequently  an  azygous  vessel,  called  the  Middle 
Articular  artery,  which  arises  from  the  back  of  the  popli- 
teal, and  is  distributed  to  the  posterior  parts  of  the  arti- 
culation. 

The  POPLITEAL  artery,  after  this,  sends  off  a few 
small  branches  to  the  heads  of  the  muscles  of  the  leg,  and 
among  them  one  of  considerable  length,  to  each  of  the 
heads  of  the  gastroc  nemii.  At  the  under  edge  of  the 
popiiteus  muscle,  it  sends  off  horizontally  a large  branch 
which  passes  directly  forward  between  the  tibia  and  fibula, 
above  the  commencement  of  the  interosseous  ligament. 
After  this  it  continues  to  descend,  nearly  in  the  same  di- 
rection, under  the  soleus  muscle,  behind  the  tibia;  but 
before  it  has  proceeded  further  than  twelve  or  fifteen 
lines,  it  sends  off  a branch  which  forms  an  acute  angle 
with  it,  and  approaches  near  the  fibula,  along  which  it 
descends. 

The  branch  sent  off  anteriorly,  is  called  the  anterior 
tisial  artery. 

The  main  trunk,  which  continues  downwards,  is  called 
the  posterior  tibial  artery; 


285 


Anterior  Artery  of  the  Leg. 

And  the  branch  which  descends  near  the  fibula  is  called 
the  Peroneal  or  Fibular  artery. 


The  anterior  tibi al  Artery, 

After  its  arrival  on  the  anterior  part  of  the  leg,  passes 
down  close  to  the  interosseous  ligament,  with  the  tibialis 
anticus  muscle  on  the  inside,  and  the  extensor  communis 
on  the  outside,  in  the  first  part  of  its  course;  and  after- 
wards, with  the  extensor  pollicis  pedis  on  the  outside  of 
it.  It  gradually  inclines  internally  as  it  descends,  so  that 
a little  above  the  ankle  it  is  upon  the  front  part  of  the 
tibia.  It  proceeds  thence  with  the  tendons  of  the  extensor 
digitorum  pedis,  under  the  annular  ligament,  to  the  upper 
surface  of  the  foot,  on  which  it  continues  to  the  interstice 
of  the  first  and  second  metatarsal  bones,  where  it  descends 
to  anastomose  in  the  way  presently  to  be  mentioned. 

In  this  course  it  sends  off,  soon  after  it  has  arrived  at 
its  anterior  situation,  a recurrent  branch , which  is  distri- 
buted to  the  heads  of  the  muscles  and  the  ligaments  of 
the  articulation,  and  which  anastomoses  with  the  branches 
of  the  inferior  articular  arteries.  It  also  sends  off,  on  each 
side,  many  arterial  twigs  to  the  contiguous  muscles,  and 
very  frequently  one  branch  of  considerable  size,  which 
passes  down  near  the  fibula. 

When  it  has  arrived  near  the  end  of  the  tibia,  it  sends 
a branch  on  each  side,  called  the  Internal  and  External 
Malleolar.  On  the  top  of  the  foot,  among  several  smaller 
arteries,  it  sends  off  a branch  under  the  extensor  brevis 
digitorum  pedis,  which  passes  outwards  and  forwards, 
and  supplies  the  muscles,  &c.,  on  the  upper  part  of  the 
foot.  This  vessel  is  called  Arteria  Tarsea.  There  is  also 
another  branch,  called  Metatarsea , which  generally  arises 
about  the  middle  of  the  foot,  and  passes  obliquely  out- 
ward and  forward,  supplying  the  contiguous  parts. 

The  anterior  tibiae  artery,  having  arrived  at  the 


286 


Posterior  Tibial  and  Peroneal  Arteries. 


space  between  the  metatarsal  bones  of  the  first  and  second 
toes,  bends  down  to  the  sole  of  the  foot,  but  previously 
sends  off  a branch  which  passes  near  the  external  edge  of 
the  metatarsal  bone  of  the  great  toe,  and  divides  into  two 
branches,  one  of  which  goes  to  the  outside  of  the  great 
toe,  and  the  other  to  the  opposite  side  of  the  toe  next  to 
it. 


The  posterior  tibial  Artery , 

After  sending  off  the  anterior  tibial,  parts  with  the  Pero- 
neal or  Fibular,  as  has  been  already  stated,  and  then  con- 
tinues on  the  back  of  the  tibia,  behind  the  internal  ankle, 
to  the  sole  of  the  foot. 

The  Peroneal  or  Fibular  Artery 

Is  not  commonly  so  large  as  either  of  the  two  other 
arteries  of  the  leg,  nor  is  it  so  constant.  It  passes  down 
very  near  the  internal  edge  of  the  fibula.  If  is  in  contact, 
for  some  distance,  with  the  tibialis  posticus  muscle,  and 
is  anterior  to  the  soleus  and  the  flexor  pollicis  longus;  it 
sends  branches  to  the  contiguous  muscles.  After  it  has 
passed  along  two  thirds  of  the  length  of  the  fibula,  it 
frequently,  but  not  always,  divides  into  an  anterior  and 
a posterior  branch. 

The  anterior  peroneal  soon  perforates  the  interosseous 
ligament,  and  passing  down  some  distance  on  its  anterior 
surface,  continues  to  the  ankle  and  upper  surface  of  the 
foot.  It  gives  ramifications  to  all  the  contiguous  parts  in 
its  progress,  and  anastomoses  with  some  of  the  small  ra- 
mifications of  the  tibialis  antica. 

The  posterior  peroneal  branch  is  the  continuation  of  the 
main  trunk.  It  passes  behind  the  external  malleolus,  and 
ramifies  upon  the  external  side  of  the  foot. 

The  posterior  tibial  artery  passes  down,  inclining 


287 


Arteries  of  the  Foot. 

rather  obliquely  inwards,  between  the  gastroc  nemius 
internus,  which  is  posterior  to  it,  and  the  tibialis  posticus 
and  flexor  digitorum,  which  are  anterior  to  it.  Upon  the 
leg  it  gives  off  many  small  branches,  one  of  which,  termed 
the  Arteria  Nutritia  Tibia,  comes  off  high  up,*  and,  after 
ramifying  as  it  descends,  sends  a branch  to  the  medullary 
foramen  of  the  tibia. 

At  the  lower  part  of  the  leg  the  posterior  tibial  is 
situated  rather  superficially 'between  the  tendo  Achillis 
and  the  tibia.  It  proceeds  thence  behind  the  internal  ankle 
in  a deep  situation,  covered  by  an  annular  ligament,  and 
passes  between  the  abductor  muscle  of  the  great  toe  and 
the  bones  of  the  tarsus.  It  then  divides  into  two  branches 
— the  internal  and  the  external  plantar  arteries. 


The  Internal  Plantar  Artery 

Is  commonly  much  smaller  than  the  other  ramification. 
It  passes  in  the  direction  of  the  internal  edge  of  the  foot, 
but  at  some  distance  from  it,  and  often  lies  between  the 
aponeurosis  plantaris  and  the  abductor  pollicis.  It  fre- 
quently terminates  by  anastomosing  with  one  of  the  arte- 
ries of  the  great  toe,  and  in  its  course  sends  off  several 
branches  to  the  contiguous  parts  on  each  side  of  it. 

The  External  Plantar  Artery 

Is  the  continuation  of  the  main  trunk.  It  proceeds  out- 
wards and  forwards  between  the  short  flexor  of  the  toes 
and  the  flexor  accessorius;  and  continues  afterwards  be- 
tween the  first  of  these  muscles  and  the  abductor  of  the 
little  toe.  At  the  metatarsal  bone  of  the  little  toe  it  begins 
to  curve,  and  continues  its  curvature  across  the  other 
metatarsal  bones  to  the  interstice  between  the  great  toe 

* This  artery  sometimes  comes  off  from  the  popliteal. 


288 


Arteries  of  the  Foot. 

and  the  one  next  to  it,  passing  between  the  tendons  of  the 
long  extensor  and  the  metatarsal  bones.  At  the  interstice 
above  mentioned,  it  anastomoses  with  the  tibialis  antica. 
The  curvature,  thus  formed,  is  called  the  Arcus  Plantaris. 

In  this  course,  the  External  Plantar  sends  off  several 
branches  to  the  heel  and  the  parts  of  the  foot,  especially 
on  the  external  side;  the  deep  seated  parts  of  the  foot  be- 
ing supplied  from  the  curve. 

Digital  branches  go  off  from  the  curve,  as  they  do  in 
the  hand,  from  the  curve  of  the  ulnar.  There  is  first  a 
small  branch  to  the  outside  of  the  little  toe;  and  then  three 
regular  branches,  which  pass  to  the  junction  of  the  roots 
of  the  four  small  toes,  and  divide,  like  the  digital  arteries 
of  the  hand,  so  as  to  send  a branch  to  the  side  of  each  toe. 
These  digital  arteries  pass  between  the  muscle  called 
Transversalis  Pedis  and  the  metatarsal  bones.  Near  the 
heads  of  these  bones,  each  of  them  generally  sends  off 
two  arteries  that  pass  upwards  between  the  interossei 
muscles  and  the  bones,  and  anastomose  with  the  ramifica- 
tions from  the  top  of  the  foot. 

1 he  External  Plantar , soon  after  sending  off  the  third 
digital  artery,  anastomoses  with  the  anterior  tibial,  and 
then  continues  to  the  junction  of  the  root  of  the  great  toe 
with  the  one  next  to  it,  when  it  divides  into  two  branches, 
which  go  to  the  opposite  sides  of  those  toes.  In  its  course 
it  also  sends  a branch  to  the  internal  side  of  the  great  toe. 


CHAPTER  III. 


OF  THE  PARTICULAR  DISTRIBUTION  OF  THE  VEINS. 

ANATOMISTS  of  great  respectability  have  very  dif- 
ferent sentiments  lespecting  the  best  method  of  describing 
the  veins.  Some  of  them,  in  order  to  follow  the  course  of 
the  circulation,  commence  with  the  small  veins,  and  pro- 
ceed to  the  large  trunks  which  are  formed  by  their  union. 
Others  begin  with  the  great  veins  that  empty  into  the 
heart,  and  proceed  from  them  to  the  small  ramifications 
of  the  venous  system,  in  a direction  the  reverse  of  the 
circulation. 

As  the  last  method  is  the  easiest  for  the  student  of 
anatomy,  it  will  be  adopted  here;  but  it  must  always  be 
kept  in  mind,  that  the  blood  flows  from  the  small  veins 
into  the  larger,  and  not  from  the  latter  into  the  former, 
as  the  mode  of  description  seems  to  imply. 

The  great  trunk  of  the  venous  system  differs  consi- 
derably from  that  of  the  arterial  with  respect  to  its  con- 
nexion with  the  heart;  for  it  communicates  with  that  organ 
in  such  a manner  that,  when  viewed  from  before,  it  ap- 
pears like  two  vessels;  one  opening  into  the  upper,  and 
the  other  into  the  lower  part  of  the  right  auricle.  When 
viewed  from  behind,  it  appears  like  a continued  tube, 
three  fourths  of  which  are  deficient  anteriorly;  and  to  the 
margin  of  this  deficiency  the  right  sinus  or  pouch  of  the 
heart  is  connected. 

In  some  preparations  of  the  heart,  where  all  the  great 
vessels  connected  with  it  are  much  distended  by  the  in- 
jection, and  the  pulmonary  vessels  are  injected  first;  the 
right  auricle  is  so  much  pressed  upon  from  behind,  by 
Vol.  II.  2 0 


290 


V sins  of  the  Heart. 

the  vessels  which  go  to  the  right  lung,  that  the  direction 
of  the  superior  and  inferior  portions  of  the  vena  cava, 
which  thus  communicate  with  it,  is  altered.  Each  of  them 
is  turned  obliquely  forwards,  so  that  it  forms  an  angle 
with  the  other.  This  occasions  them  to  appear  more  like 
distinct  vessels  than  they  otherwise  would  do. 

The  above  mentioned  portions  of  the  great  veins  are 
denominated  the  Superior  or  Descending , and  the  Inferior 
or  Ascending  Vena  Cava;  as  if  they  were  perfectly  distinct 
and  unconnected  with  each  other. 


The  coronary  Veins , 

Which  are  exclusively  appropriated  to  the  heart,  may  be 
considered  here,  as  they  are  not  included  in  the  general 
arrangement  of  the  veins. 

The  great  vein  of  the  heart  begins  at  the  lower  part  of 
the  right  auricle,  very  near  to  the  septum,  which  divides 
the  two  auricles.  It  soon  proceeds  to  the  left,  in  a circular 
direction,  surrounded  with  adipose  matter,  in  the  deep 
groove  which  exists  between  the  left  auricle  and  the  left 
ventricle.  It  continues  between  1:116  auricle  and  ven- 
tricle, until  it  is  immediately  over  the  septum,  which 
divides  the  two  ventricles.  Here  its  direction  changes, 
and  it  proceeds  to  the  apex  of  the  heart,  where  its  small 
ramifications  anastomose  with  others  soon  to  be  described. 
In  its  course  round  the  basis  of  the  left  ventricle,  it  sends  off 
several  branches,  one  of  which  is  considerable,  that  pro- 
ceed from  the  basis  towards  the  apex  of  the  heart,  rami- 
fying on  the  surface  of  the  left  ventricle. 

A second  vein,  much  less  than  the  first,  appears  to  pro- 
ceed from  the  great  vessel  at  its  commencement,*  and 
continues  on  the  lower  flat  surface  of  the  heart,  between 
the  two  ventricles,  to  the  apex,  accompanied  by  a branch 


* It  often  opens  into  the  auricle  by  a separate  orifice. 


Superior  Vena  Cava  and  its  Great  Branches.  291 

of  the  right  coronary  artery.  This  has  been  called  the 
Middle  vein  of  the  heart. 

In  addition  to  these  there  are  several  veins. which  begin 
at  the  right  auricle,  and  extend  on  the  surface  of  the  right 
ventricle  towards  the  apex  of  the  heart.  These  have  been 
called  the  Anterior  Veins. 


SECTION  I. 

Of  the  SUPERIOR  or  DESCENDING  VENA 

CAVA,  and  the  Veins  which  communicate  with  it. 

THIS  great  vessel  proceeds  upwards  from  the  superior 
and  posterior  part  of  the  right  sinus  or  pouch  of  the  heart;* 
and  a portion  of  it  is  so  involved  by  the  pericardium,  that 
it  seems  to  be  included  in  that  sac,  as  the  heart  is  in  this 
situation.  It  is  somewhat  anterior  as  W'ell  as  to  the  right 
of  the  aorta.  It  continues  above  the  pericardium,  adhering 
to  the  right  lamina  of  the  mediastinum,  and  rather  inclining 
forward.  When  it  is  as  high  as  the  lower  margin  of  the 
upper  rib,  it  sends  off  a very  large  branch,  which  conveys 
the  venous  blood  of  the  left  arm  and  the  left  side  of  the 
head  and  neck.  This  large  vein,  which  is  very  important, 
both  on  account  of  its  size  and  its  situation,  proceeds  in  a 
transverse  direction  within  the  sternum,  almost  in  contact 
with  and  but  little  below  the  upper  and  internal  margin 
of  that  bone.  Immediately  behind  or  within  the  origin  of 
the  left  sterno-mastoid  muscle,  it  divides  into  the  left  sub- 
clavian, which  preserves  a transverse  course,  and  the  left 
internal  jugular,  which  proceeds  to  the  cavity  of  the 
cranium  by  the  foramen  lacerum. 


*See  the  description  of  the  heart,  in  page  50,  of  this  volume. 


292 


Vena  Azygos. 

After  sending  off  this  transverse  branch  to  the  left,  the 
great  vein  continues  upwards  and  behind  the  right  sterno- 
mastoid  muscle,  and  there  sends  off,  nearly  at  right  angles, 
the  right  subclavian  vein.  After  it  has  parted  with  this 
vein,  it  takes  the  name  of  Internal  Jugular , and  continues 
to  the  right  foramen  lacerum,  in  the  basis  of  the  cranium. 
—The  superior  vena  cava  is,  therefore,  principally  formed 
by  the  union  of  the  subclavians  and  internal  jugulars  from 
each  side  of  the  body. 

Immediately  after  the  superior  cava  rises  above  the 
pericardium,  before  it  divides  as  above  stated,  it  sends  off, 
from  its  posterior  part,  a large  vein  which  is  single,  and 
therefore  called 

VENA  AZYGOS. 

This  vessel  projects  backward  above  the  right  pulmo- 
nary artery  and  right  branchof  the  trachea,  and  then  curves 
downwards  behind  them.  It  proceeds  down  the  spine  to 
the  right  of  the  aorta  and  at  a small  distance  from  it,  into 
the  abdomen,  between  the  crura  of  the  diaphragm,  and 
sometimes  between  some  of  the  portions  of  that  muscle, 
which  are  attached  to  the  dorsal  vertebras.  In  the  abdomen 
it  often  anastomoses  either  with  the  lumbar  veins  or  the 
vena  cava. 

The  azygos  frequently  sends  off  several  small  veins 
from  its  curvature  to  the  contiguous  parts,  and  also  the 
right  Bronchial  Vein , which  passes  along  the  ramifications 
of  the  trachea  into  the  substance  of  the  lungs.*  In  its 
course  downwards  it  gives  off  branches  to  the  oesophagus, 
some  of  which  are  considerable. 

The  Inferior  Intercostal  Veins  originate  directly  or  in- 
directly from  the  azygos.  In  seme  cases  there  is  no  Su- 
perior Intercostal  on  the  right  side;  and  then  the  two  or 


This  bronchial  vein  sometimes  arises  from  the  superior  cava. 


293 


Inferior  Intercostal  Veins . 

three  uppermost  of  the  right  intercostals  are  also  derived 
from  the  azygos;  and  often  originate  from  it  by  a common 
trunk,  which  soon  divides. 

Most  commonly  the  ten  inferior  intercostals  on  the 
right  side  proceed  directly  from  the  azygos,  and  accom- 
pany the  intercostal  arteries.  Their  posterior  branches 
pass  into  the  vertebral  cavity,  and  communicate  with  the 
veins  which  are  there. 

About  the  sixth  or  seventh  rib,  the  vena  azygos  fre- 
quently sends  off  a branch  to  the  left  which  descends  on 
the  left  side  of  the  vertebrae,  and  sends  off  those  Lejt  in- 
tercostal veins  which  are  below  its  origin.  It  passes 
through  the  diaphragm  with  the  aorta,  or  to  the  left  of  it, 
and  anastomoses  either  with  the  azygos  itself,  or  in  a way 
which  is  analogous  to  the  anastomosis  of  that  vessel. 

The  vena  azygos  may  be  regarded  as  the  great  trunk 
of  the  veins  of  the  parietes  of  the  thorax,  which  are  thus 
collected,  because  they  could  not  with  convenience  pass 
singly  to  the  vena  cava,  as  the  arteries  do  to  the  aorta. 

Soon  after  sending  off  the  vena  azygos,  the  Superior 
Cava  sends  off  the  great  transverse  branch  above  mention- 
ed. From  this  it  continues  upwards  but  a short  distance, 
when  it  divides,  behind  the  right  sterno  mastoid  muscle, 
into  the  right  subclavian  and  right  internal  jugular. 

The  branches  of  the  superior  cava,  which  thus  inter- 
vene between  the  great  trunk  and  the  subdivisions  behind 
the  sterno- mastoid  muscles,  are  often  called  the  Subclavian 
Feins;  but  they  do  not  appear  to  be  accurately  named. 
For,  1st,  they  are  not  situated  under  the  clavicle,  and, 
2dly,  they  are  the  common  trunks  of  the  subclavians  and 
internal  jugulars  united. 

There  is  a difference  in  the  places  where  some  of  the 
smaller  veins  originate  on  each  side.  The  internal  mam- 
mary and  the  inferior  thyroid,  on  the  right  side,  arise 
from  the  superior  cava,  or  from  the  subclavian  at  its 
origin.  On  the  left  side  they  arise  from  the  subclavian. 


294 


Superior  Intercostal  Veins. 


The  superior  intercostal  Veins 

Are  somewhat  different  on  the  two  sides.  That  on  the 
right  is  often  the  smallest  and  the  least  extensive.  It  com- 
monly originates  from  the  posterior  and  inferior  part  of 
the  subclavian  opposite  to  the  origin  of  the  vertebral,  and 
is  generally  distributed. to  the  first  and  second  intercostal 
spaces,  but  rarely  to  the  third. 

The  Left  Intercostal  frequently  originates  near  the  left 
internal  mammary,  and  sometimes  in  common  with  it.  It 
descends  behind  the  aorta,  on  the  left  of  the  spine,  and 
commonly  sends  off  the  six  upper  intercostal  veins,  of 
which  the  two  or  three  superior  pass  upwards  from  a part 
of  the  vein  which  is  opposite  to  the  third  dorsal  vertebra. 
Its  extent  is  very  different  in  different  subjects.  In  some 
instances  it  passes  so  low  as  to  supply  the  seventh  or 
eighth  intercostal  space.  This  vein  also  gives  off  the  Left 
Bronchial  Vein , which  sends  branches  to  the  oesophagus 
and  bronchial  glands. 

The  vertebral  Veins 

Arise  from  the  subclavians,  but  sometimes  they  proceed 
differently  in  different  subjects:  the  right  passing  behind, 
and  the  left  before,  the  subclavian  artery  of  its  respective 
side.  Each  of  them,  however,  becomes  contiguous  to  its 
corresponding  artery.  When  it  has  arrived  at  the  place  in 
the  transverse  processes,  where  the  artery  enters  the  ver- 
tebral canal,  it  sends  off  an  external  branch,  which  passes 
up,  before  and  nearly  in  contact  with,  those  processes, 
and  gives  ramifications  to  the  contiguous  muscles,  and 
also  to  the  cavity  of  the  spine.  These  last  mentioned 
ramifications  enter  by  the  lateral  apertures  between  the 
transverse  processes,  and  anastomose  with  the  veins  and 
sinuses  of  the  cavity.  The  branch  often  finally  terminates 


Vertebral  Veins . 


295 


in  the  lateral  sinus  of  the  dura  mater,  by  passing  through 
the  foramen  near  the  mastoid  process  of  the  temporal 
bone.  The  Main  Trunk  of  the  vertebral  vein  generally 
sends  off  another  external  branch  to  the  muscles  near  the 
basis  of  the  neck,  and  afterwards  enters  the  canal  with 
the  vertebral  artery.  While  in  this  canal,  it  generally  sends 
off  two  branches  through  each  of  the  lateral  apertures  be- 
tween the  vertebras.  One  of  these  branches  passes  back- 
wards to  the  muscles  of  the  neck;  and  the  other  proceeds 
into  the  great  spinal  cavity,  and  communicates  with  the 
venous  sinuses. 

When  it  has  arrived  at  the  atlas,  the  vertebral  vein 
sends  branches  to  the  contiguous  muscles  of  the  neck.  It 
also  frequently  sends  a branch  through  the  posterior  con- 
dyloid foramen  of  the  occipital  bone  to  the  lateral  sinus. 

It  is  evident,  from  these  circumstances,  that  the  verte- 
bral vein  carries  a portion  of  blood  from  the  sinuses  of 
the  brain  and  of  the  spinal  marrow,  as  well  as  from  the 
muscles  of  the  neck,  into  the  subclavian  veins. 

The  veins  of  the  head  are  frequently  very  different  in 
different  subjects. 

The  INTERNAL  JUGULAR, , 

Already  mentioned,  is  often  almost  exclusively  appro- 
priated to  the  cavity  of  the  cranium:  and  all  the  exterior 
veins  of  the  head  are  ramifications  of  one  or  more  smaller 
vessels,  which  pass  up  superficially  on  the  neck,  and  are 
denominated  External  Jugulars.  In  some  instances  almost 
all  the  exterior  veins  of  the  head  are  united  to  the  internal 
jugular  at  the  upper  part  of  the  neck,  and  it  of  course 
conveys  the  blood  of  the  exterior  as  well  as  of  the  interior 
parts  of  the  head.  Frequently  these  veins  are  divided  be- 
tween the  internal  and  external  jugulars,  but  they  are 
divided  very  differently  in  different  subjects. 

The  Internal  Jugular , however,  almost  always  passes 


296 


The  Internal  Jugular. 

in  the  same  direction  from  the  inside  of  the  origin  of  the 
sterno-mastoid  muscle  to  the  posterior  foramen  lacerum 
of  the  cranium.  It  is  deeply  seated  on  the  external  side  of 
the  common  carotid  artery,  and  under  the  sterno-mastoid 
muscle.  Between  the  upper  margin  of  the  thyroid  car- 
tilage and  the  angle  of  the  lower  jaw,  it  often  sends  off 
branches  which  are  very  different  in  different  subjects, 
but  commonly  pass  to  the  anterior  parts  of  the  neck  and 
face:  above  these  it  generally  sends  another  to  commu- 
nicate  with  the  external  jugular.  One  of  the  branches 
which  often  go  off  from  the  internal  jugular  is  that  which 
corresponds  with  the  superior  thyroid  or  laryngeal  artery. 
This  vein,  which  has  sometimes  been  called  the  Gut- 
tural, sends  many  ramifications  to  the  thyroid  gland.  The 
Ranular  veins,  which  are  so  conspicuous  under  the 
tongue,  are  also  derived  from  it;  and  it  likewise  sends 
branches  to  the  larynx  and  pharynx. 

Before  the  internal  jugular  enters  the  foramen  lacerum, 
it  suffers  a partial  dilatation,  which  is  generally  larger  on 
one  side  than  the  other.*  This  dilatation  occupies  the 
fossa  at  the  foramen  lacerum.  After  passing  through  the 
aforesaid  foramen,  the  internal  jugular  terminates  in  the 
lateral  sinuses  of  the  dura  mater. f These  and  the  other 
sinuses  within  the  cavity  of  the  cranium  are  important 
portions  of  the  venous  system,  which  are  interposed  be- 
tween the  smaller  branches  spread  upon  the  pia  mater 

* When  the  veins  of  the  neck  are  injected  it  very  often  appears 
that  a considerable  portion  of  the  internal  jugular  is  much  larger  on 
one  side  than  the  other,  as  if  it  were  affected  with  varicose  disten- 
tion. 

It  also  often  appears  that  the  general  arrangement  of  the  exterior 
vein  is  different  on  the  two  sides  of  the  head  and  neck. 

f It  is  asserted  that  the  internal  coat,  or  lining  membrane  of  the 
internal  jugulars,  is  continued  into  the  lateral  sinuses,  and  extends 
throughout  all  the  sinuses  of  the  dura  mater;  so  that  the  blood,  during 
its  passage  through  the  sinuses,  does  not  come  in  contact  with  any 
membrane  different  from  that  of  the  veins. 


297 


The  External  Jugular. 

and  the  great  trunks  of  the  neck.  They  are  described  in 
the  account  of  the  brain,  (Vol.  I.  p.  308).  Into  these 
sinuses  the  very  numerous  veins  of  the  pia  mater  open, 
proceeding  to  the  sinuses*  in  a direction  the  reverse  of 
that  in  which  the  blood  flows  in  those  channels. 

These  veins  are  divided  very  minutely  on  the  pia  mater 
before  they  enter  the  substance  of  the  brain. 

Into  one  of  these  sinuses,  denominated  the  Cavernous , 
the  ophthalmic  vein  discharges  its  contents.  This  vein 
proceeds  from  the  anterior  part  of  the  sinus  into  the  orbit 
of  the  eye  through  the  sphenoid  fissure.*  Its  ramifications 
correspond  generally  with  those  of  the  ophthalmic  arteryf 
and  some  of  them  pass  out  of  the  orbit  to  anastomose 
with  the  branches  of  the  facial  vein. 

The  superficial  veins  of  the  neck  are  variously  arranged 
in  different  persons.  There  is  often  one  considerable  vein, 

The  EXTERNAL  JUGULAR, , 

Which  is  sent  off  by  the  subclavian,  very  near  its  union 
with  the  internal  jugular;  but  sometimes  it  goes  off  from 
that  vein  much  nearer  the  shoulder.  There  are  sometimes 
two  external  jugulars,  an  anterior  and  a posterior,  nearly 
of  equal  size.  More  frequently  one  of  them  is  much 
smaller  than  the  other.  In  a majority  of  cases,  the  princi- 
pal external  jugular  goes  off"  near  the  junction  of  the  internal 
jugular  and  subclavian,  as  above  stated,  and  proceeds  up- 
wards towards  the  angle  of  the  lower  jaw,  passing  between 
the  platysma  myoides  and  the  sterno- mastoid  muscle.  It 
often  sends  off,  at  the  basis  of  the  neck,  one  or  more 
branches  to  the  contiguous  muscles,  and  then  proceeds 
upwards.  Near  the  angle  of  the  jaw,  it  often  communi- 

* See  the  account  of  this  fissure  in  Vol.  I.  p.  53. 

t The  Vasa  Vorticosa  of  the  choroides  are  one  of  the  exceptions  to 
this.  See  Vol.  I.  p.  342. 

Vol.  II.  2 P 


298  General  Account  of  the  Great  Vein  of  the  Arm « 

cates  with  the  internal  jugular:  it  then  continues  upwards, 
covered  with  the  parotid  gland,  near  the  temporal  artery, 
and  finally  divides  into  superficial  and  deep-seated  tem- 
poral branches. 

The  External  Jugular,  near  the  angle  of  the  jaw,  often 
sends  olf  the  facial  vein,  which  crosses  the  basis  of  the 
lower  jaw,  near  the  facial  artery,  and  distributes  branches 
to  the  side  of  the  face  and  to  the  forehead.  It  also  very 
often  sends  off,  near  this  place,  the  internal  maxillary 
vein,  which  generally  ramifies  in  such  a manner  that  its 
branches  correspond  with  those  of  the  internal  maxillary 
artery.  Veins  which  correspond  to  some  of  the  other 
branches  of  the  external  carotid  artery,  the  lingual,  occi- 
pital, &c.,  are  often  sent  off  near  this  place  by  the  external 
jugular.  They  take  the  names  of  the  arteries  to  which 
they  correspond,  and  commonly  accompany  them. 

The  SUBCLAVIAN  Vein , 

Although  it  originates  differently  on  the  two  sides  of  the 
neck,  is  situated  alike  on  each  of  them.  After  parting 
with  the  internal  jugular,  it  proceeds  over  the  first  rib, 
under  the  clavicle,  and  does  not  pass  between  the  scaleni 
muscles,  as  is  the  case  with  the  arteries,  but  before  the 
anterior  muscle.  It  soon  joins  the  great  artery  of  the  arm, 
and  proceeds  before  or  below  it  to  the  axilla.  In  this 
situation  it  gives  off  branches  to  the  contiguous  parts, 
which  correspond  with  those  given  off  by  the  artery.  In 
this  course  it  also  often  gives  off  a large  branch,  called  the 

CEPHALIC, 

Which  soon  becomes  superficial,  and  proceeds  down- 
wards between  the  margins  of  the  deltoid  and  pectoral 
muscles:  it  continues  superficial  on  the  external  side  of 
the  biceps  muscle,  sending  off  many  subcutaneous 


General  Account  of  the  Great  Vein  of  the  Arm.  299 

branches.  Near  the  external  condyle  of  the  os  humeri,  it 
generally  sends  off  a branch  towards  the  middle  of  the  an- 
terior part  of  the  fore  arm,  which  is  called  the  Median 
Cephalic , and  also  some  other  superficial  branches.  It  then 
continues  over  the  radius,  and  inclining  to  the  back  of 
the  fore  arm,  until  it  arrives  at  the  back  of  the  hand, 
where  it  divides  into  branches,  some  of  which  go  to  the 
thumb. 

In  the  axilla,  the  great  vein,  there  called 
The  AXILLARY  Vein 

Generally  divides  into  two  or  three  branches.  One,  which 
is  commonly  the  largest,  and  appears  like  the  continuation 
of  the  main  trunk,  is  called 


The  basilic  Vein . * 

This  vessel  passes  down,  deeply  seated,  to  the  bend  of 
the  elbow.  It  becomes  superficial  near  the  internal  condyle, 
and  divides  into  several  branches.  One  of  these  generally 
proceeds  to  join  the  median  branch  of  the  cephalic,  and 
from  the  union  of  the  two  branches  is  formed  the  median 
vein,  which  passes  down  near  the  middle  of  the  anterior 
part  of  the  fore  arm.  This  vein  generally  sends  off  a branch 
which  proceeds  internally,  and  anastomoses  with  the  deep- 
seated  veins  of  the  fore-arm. 

There  are  frequently  two  other  branches  of  the  basi- 
lic vein.  One,  which  is  small,  passes  down  on  the  ulnar 
side  of  the  anterior  part  of  the  fore-arm,  but  does  not  ex- 
tend to  the  wrist.  The  other  passes  down  on  the  ulna,  and 
gradually  proceeds  to  the  back  of  the  hand,  when  it  di- 
vides into  several  branches,  one  of  which  is  generally  ap- 
propriated to  the  little  finger. 

The  AXILLARY  vein,  after  the  basilic  leaves  it, 
sometimes  divides  into  two  branches,  and  sometimes  con- 


300  Situation  of  the  Inferior  Vena  Cava . 

tinues  undivided.  In  either  case  it  accompanies  the  hu- 
meral artery,  and  takes  the  name  of  HUMERAL  Vein 
or  Veins.  It  sends  oft'  branches  which  correspond  to  those 
of  the  artery,  and  continues  to  the  bend  of  the  elbow: 
here  it  is  so  divided,  that  two  of  its  ramifications  accom- 
pany each  of  the  three  arteries  of  the  fore-arm.  These 
ramifications  sometimes  communicate  with  each  other 
by  anastomosing  branches  near  the  elbow,  and  they  com- 
municate also  with  the  superficial  veins. 

The  superficial  veins  of  the  arm  are  so  different  in  different 
subjects,  that  a general  description  will  rarely  apply  ac- 
curately to  an  individual  case.  It  may,  however,  be  ob- 
served, that  a Cephalic  vein  will  generally  be  found,  which 
very  frequently  arises  from  the  subclavian  instead  of  the 
axillary,  and  commonly  continues  to  the  hand  on  the  ra- 
dial side  of  the  arm.  The  superficial  veins,  on  the  ulnar 
side  of  the  fore-arm,  very  frequently  are  branches  of  a 
large  vein  which  accompanies  the  humeral  artery  to  the 
elbow,  viz.,  the  basilic;  but  the  median  vein,  formed  by 
branches  of  the  cephalic  and  basilic  veins,  is  very  often 
not  to  be  found. 


SECTION  II. 

Of  the  INFERIOR  VENA  CAVA,  and  the  Veins 
xvhich  are  connected  with  it. 

THIS  great  vessel  exceeds  the  Superior  Cava  in  di- 
ameter. It  proceeds  from  the  lower  part  of  the  right  auricle, 
and  verv  soon  perforates  the  diaphragm,  at  a small  distance 
in  front  of  the  spine,  and  rather  to  the  right  of  the  center. 
As  the  pericardium  adheres  to  the  diaphragm  at  this  place, 
the  vessel  appear  i to  leave  it  abruptly.  Immediately  after 
leaving  the  diaphragm,  it  proceeds  along  a groove  in  the 
posterior  edge  of  the  liver,  formed  by  the  great  lobe  and 


301 


Situation  of  the  Inferior  Vena  Cava. 

the  lo.bulus  Spigelii.*  After  leaving  the  liver,  it  continues 
downwards,  inclining  backward  and  to  the  left,  and  is  soon 
in  contact  with  the  aorta,  which  is  on  the  left  of  it.  It  ac- 
companies the  aorta  to  its  great  bifurcation,  and  divides 
in  the  same  manner.  It  sends  olf,  during  this  course, 
branches  to  the  Diaphragm,  Liver,  Right  Renal  Gland, 
the  Kidneys,  and  the  Testicles;  and  also  the  Lumbar  and 
Middle  Sacral  veins. 

The  Inferior  Phrenic  V eins 

Are  thus  denominated  to  distinguish  them  from  other 
veins,  which  are  derived  from  the  internal  mammary,  &c. 
They  generally  accompany  the  phrenic  arteries,  and  are 
distributed  in  the  same  manner. 

The  HEPATIC  Veins 

Pass  off  from  the  vena  cava,  nearly  at  right  angles,  into 
the  substance  of  the  liver,  while  it  is  in  the  groove  of  that 
viscus,  and  before  it  has  proceeded  more  than  eight  or 
ten  lines  from  the  heart. 

They  arise  from  the  anterior  part  of  the  vena  cava,  and 
are  generally  three  in  number.  Sometimes  there  are  two 
only,  but  then  one  of  them  divides  immediately  after  it 
enters  the  substance  of  the  gland. 

The  distribution  of  these  vessels  in  the  liver  has  been 
detailed  in  the  account  of  that  organ,  and,  therefore,  need 
not  be  stated  here;  but  the  veins  which  unite  to  form  the 
vena  portarum,  and  the  trunk  of  that  great  vein  also,  be- 
fore it  is  connected  with  the  liver,  may  be  regarded  as  a 
portion  of  the  regular  venous  system,  and  ought  now  to 
be  considered. 

* Sometimes  it  is  completely  surrounded  by  the  liver. 


302 


Superior  Mesenteric  Vein • 


The  VENA  PORT  ARUM 

Passes  downwards  from  die  great  sinus  of  the  liver  behind 
the  pancreas,  and  inclining  to  the  left.  In  this  course  it 
sends  branches  to  die  gall  bladder,  the  stomach  and  pylo- 
rus, and  the  duodenum.  At  the  upper  and  posterior  edge 
of  the  pancreas,  it  sends  off  a very  large  branch  to  the 
spleen,  which  often  passes,  with  slight  meanders,  along  a 
groove  in  the  pancreas. 

The  SPLENIC  Vein 

Often  ^ends  off  the  inferior  mesenteric  vein,  which 
proceeds  downwards  between  the  aorta  and  the  left  por- 
tion of  the  colon.  It  also  sends  off  some  of  the  coronary 
veins  and  the  left  gastro  epiploic  vein  to  the  stomach; 
many  small  branches  to  the  pancreas;  and,  finally,  either 
from  the  main  trunk  or  its  branches  before  they  enter  the 
spleen,  the  venae  breves,  which  pass  to  the  great  extremity 
of  the  stomach.  Before  it  enters  the  spleen,  it  forms  several 
ramifications,  which  accompany  the  branches  of  the 
splenic  artery. 

After  sending  off  the  splenic,  the  Vena  Portarum  takes 
the  name  of 

The  SUPERIOR  MESENTERIC  Vein; 

f 

Which  is  larger  than  the  splenic,  and  passes  from  behind 
the  pancreas , before  the  transverse  portion  of  the  duodenum , 
into  the  mesentery;  where  it  accompanies  the  superior 
mesenteric  artery. 

It  is  evident  that  the  above  described  portion  of  the 
vena  portarum  simply  performs  the  functions  of  a great 
vein;  but  when  it  takes  on  the  arrangements  for  entering 
the  liver,  it  no  longer  acts  like  a vein,  but  an  artery. 


303 


Emulgent  Veins . 

The  lower  portion  of  the  trunk  of  this  vein  and  its 
ramifications  is  denominated  Vena  Porta  Ventralis.  The 
part  which  ramifies  in  the  liver,  Vena  Porta  Hepatica. 

The  Capsular  Veins 

Are  small  vessels,  one  on  each  side.  That  on  the  right 
passes  from  the  vena  cava  to  the  right  glandula  renalis. 
That  on  the  left  arises  from  the  left  emulgent  vein. 

The  EMULGENT,  or  RENAL,  Veins 
Are  very  large  vessels;  and,  like  the  arteries,  go  off  nearly 
at  right  angles,  one  to  each  kidney. 

The  right  emulgent  vein  is  not  so  long  as  the  left,  and 
it  is  rather  anterior  to  its  corresponding  artery.  The  left 
emulgent,  in  its  course  to  the  kidney,  crosses  the  aorta, 
and  is  anterior  to  it. 

These  veins  pass  to  the  sinus  of  each  kidney,  and 
ramify  before  they  enter  it.  The  ramifications  follow  those 
of  the  arteries. 


The  Spermatic  Veins 

Arise  one  on  each  side:  the  right  from  the  vena  cava, 
and  the  left  from  the  emulgent  vein.  They  proceed  down- 
wards behind  the  peritoneum,  and  on  the  psoas  muscle 
generally  divide  into  many  branches,  which  communicate 
with  each  other  as  they  progress  downwards,  and  form 
a plexus  denominated  Corpus  Pampiniforme.  These 
branches  proceed  in  the  spermatic  cord  to  the  back  of 
the  testis.  The  principal  part  enters  the  body  of  that  gland; 
but  some  of  the  branches  go  to  the  epididymis.  In  females 
the  spermatic  vein,  like  the  artery,  passes  to  the  ovary, 
the  uterus  and  its  appendages,  See. 


304 


Internal  Iliac  and  its  Ramifications. 


The  Lumbar  V eins 

Correspond  to  the  arteries  of  the  same  name.  They  arise 
from  the  posterior  and  lateral  parts  of  the  inferior  cava, 
and  those  on  the  left  side  pass  under  the  aorta. 

The  Middle  Sacral  V ein 

Resembles  the  artery  of  the  same  name  in  its  origin  and 
distribution. 

The  INFERIOR  VENA  CAVA  accompanies  the 
aorta  to  the  space  between  the  fourth  and  fifth  lumbar 
vertebras,  and  there  it  also  divides  into  the  two 

PRIMITIVE  ILIAC  VEINS. 

The  left  vein  crosses  behind  the  artery  of  the  right  side, 
and  rather  behind  the  left  primitive  iliac  artery,  which  it 
accompanies  until  they  are  opposite  to  the  junction  of  the 
sacrum  and  ilium,  when  it  divides  again,  like  the  artery, 
into  the  internal  and  external  iliac  veins. 

The  INTERNAL  ILIAC  or  HYPOGASTRIC  Vein 

Descends  into  the  pelvis  behind  the  artery,  which  it  ac- 
companies. Its  ramifications  correspond  in  general  with 
those  of  the  artery,  and,  therefore,  need  not  be  particu- 
larly described. 

The  VEIfiE  VESICALES 

Have  such  peculiarities  that  their  ramifications  require 
particular  attention.  They  arise  from  the  hypogastric,  very 
near  the  origin  of  the  obturator,  and  are  large  as  well  as 
numerous. 

They  are  somewhat  different  in  the  two  sexes.  Ia  men 


Ramifications  of  the  External  Iliac.  305 

they  form  a remarkable  plexus  on  the  lateral  and  inferior 
portions  of  the  bladder,  and  on  the  vesiculas  seminules. 
This  plexus  extends  more  or  less  to  the  prostate:  from  it 
a number  of  veins  proceed  to  the  symphysis  of  the  os 
pubis,  which  communicate  in  their  course  with  the  pudic 
vein.  From  thence  arises  the  great  vein  of  the  penis,  which 
proceeds  in  the  groove  between  the  corpora  cavernosa, 
and  terminates  in  the  glans  penis.  This  vein  often  divides, 
near  the  root  of  the  penis,  into  two:  one  of  which  is  in  the 
groove,  and  the  other  more  superficial.* 

In  females,  the  venae  vesicales  form  a considerable 
plexus  on  each  side  of  the  bladder  and  vagina.  Many  veins 
pass  from  these  to  the  upper  portions  of  the  bladder  and 
the  contiguous  parts,  and  form  plexuses.  The  clitoris  has 
a dorsal  vein  like  the  penis,  and  it  originates  in  a manner 
analogous  to  the  dorsal  vein  of  the  male. 

The  EXTERXAL  ILIAC  Fein. 

The  great  trunk  of  the  veins  of  the  lower  extremity  pro- 
ceeds on  the  inside  of  the  artery,  under  the  crural  arch  or 
Poupart’s  ligament.  Before  it  passes  from  under  the  arch, 
it  sends  off  two  branches  which  answer  to  the  circumflex 
artery  of  the  ilium  and  to  the  epigastric  artery. 

The  Circumflex  Fein 

Arises  from  the  external  side  of  the  iliac  vein,  and  passes 
towards  the  anterior  end  of  the  spine  of  the  ilium.  It  di- 
vides into  branches  which  accompany  those  of  the  artery 
of  the  same  name. 

* The  pudic  veins  accompany  the  arteries  of  that  name.  They  com- 
municate with  the  plexus,  as  above  mentioned,  and  continue  into  this" 
penis. 

Vol.  II.  2 Q 


306 


Veins  of  the  Leg. 


The  Epigastric  Fein 

Arises  from  the  external  iliac,  and  accompanies  the  epk 
gastric  artery. — After  passing  a small  distance  inward 
and  downward,  it  turns  up  on  the  inside  of  the  abdominal 
muscles.  In  the  first  part  of  its  course  it  sends  off  some 
small  branches  to  the  spermatic  cord. 

After  passing  beyond  Poupart’s  ligament,  the  name  of 
the  great  vessel  is  changed  from  external  iliac  to 

FEMORAL  VEIN. 

It  proceeds  downwards  at  first  on  the  inside  of  the  femo- 
ral artery,  but  gradually  changes  its  relative  situation,  so 
that  in  the  thigh  and  in  the  ham  it  is  behind  or  on  the  out- 
side of  that  vessel. 

At  a short  distance  below  Poupart’s  ligament,  after 
giving  off  some  small  branches  to  the  external  organs  of 
generation,  and  to  the  glands  of  the  groin,  it  sends  off  on 
the  internal  side  of  the  thigh  a very  large  vein  which  is 
called  the 

1 ' SAPHENA  MAJOR. 

This  vein  immediately  becomes  superficial,  and  passes 
down  on  the  internal  side  of  the  thigh,  somewhat  ante- 
riorly; giving  off'  some  small  branches  to  the  contiguous 
parts,  soon  after  it  originates;  and  many  superficial  veins 
afterwards.  It  continues  along  the  inside  of  the  knee  and 
leg  to  the  internal  ankle,  the  anterior  part  of  which  it 
passes  over.  It  then  proceeds  along  the  internal  part  of  the 
upper  surface  of  the  foot  to  the  middle,  when  it  curves 
towards  the  external  edge,  and  joins  the  lesser  saphena. 
On  the  leg  and  foot  it  also  sends  off  many  branches,  which 
anastomose  with  each  other,  and  with  those  of  the  afore- 
said vein. 


Instances  of  peculiar  arrangement  of  the  V eins.  307 

The  femoral  vein,  after  parting  with  the  saphena, 
soon  sends  off  the  vena  profunda,  and  the  circumflexae 
also,  when  they  do  not  arise  from  the  profunda.  These 
veins  are  generally  larger  than  the  arteries  to  which  they 
correspond,  and  their  branches  are  more  numerous;  but 
they  observe  the  same  course. 

The  great  vein  accompanies  the  artery  down  the  thigh 
>and  through  the  perforation  in  the  biceps;  but  it  changes 
its  relative  position,  so  that  it  is  placed  behind  or  on  the 
exterior  side  of  the  artery  at  the  lower  part  of  the  thigh. 
It  is  very  often  behind  it  in  the  ham,  where,  like  the  artery, 
it  takes  the  name  of  POPLITEAL.  In  the  ham  it  sends 
off  another  superficial  vein,  which  seems  very  analogous 
to  the  basilar  vein  of  the  arm.  This  is  called 


The  Lesser  or  External  Saphena. 

It  proceeds  from  the  ham  over  the  external  head  of  the 
gastroc  nemius,  and  down  the  outside  of  the  leg,  sending 
off  many  branches  in  its  course.  It  passes  behind  the  ex- 
ternal ankle  and  near  the  exterior  edge  of  the  upper  sur- 
face of  the  foot,  about  the  middle  of  which  it  inclines  to- 
wards the  great  saphena,  and  forms  with  it  the  anastomosis 
already  mentioned. 

The  popliteal  vein,  after  passing  across  the  articulation, 
ramifies  like  the  artery,  but  sends  two  veins,  which  ac- 
company each  of  the  three  arteries  of  the  leg. 


In  a few  instances  some  of  the  larger  veins  have  been 
found  to  be  arranged  in  a manner  very  different  from  that 
which  is  commonly  observed. 

One  case  of  this  kind  has  already  been  mentioned  in  the 
account  of  the  liver,  * where  the  Vena  Port  arum  terminated 


* See  note  to  p.  135,  of  this  volume. 


308  Pulmonary  Vessels . 

in  the  Vena  Cava , below  the  liver,  without  entering  into 
it. 

Another  very  remarkable  instance  of  peculiar  arrange- 
ment is  to  be  seen  in  a preparation  now  in  the  University 
of  Pennsylvania,  in  which  the  Inferior  Cava , instead  of 
opening  into  the  lower  part  of  the  right  auricle,  passes 
behind  it,  in  the  tract  of  the  Vena  Azygos,  and  opens  into 
the  Superior  Cava,  in  the  place  where  the  Vena  Azygos 
usually  communicates  with  that  vessel,  receiving  the  In- 
tercostal Veins  in  its  course. 

In  this  preparation,  the  Hepatic  Veins  communicate 
directly  with  the  right  auricle,  at  its  lower  part;  the  middle 
and  left  hepatic  veins  forming  one  trunk  before  they  enter, 
and  the  right  vein  passing  in  singly. 

Of  the  PULMONARY  Artery  and  Veins . 

Those  portions  of  the  pulmonary  artery  and  veins 
which  are  distinct  from  the  lungs  may  be  described  very 
briefly. 

It  has  been  already  observed,*  that  the  pulmonary 
artery  arises  from  the  left  and  most  anterior  part  of  the 
basis  of  the  right  ventricle,  and  proceeds  thence  obliquely 
backwards,  inclining  gradually  to  the  left  side  for  about 
eighteen  or  twenty  lines,  when  it  divides  into  two 
branches,  which  pass  to  the  two  lungs.  This  course  places 
it  under  the  curve  of  the  aorta:  for  that  great  vessel  passes 
over  the  right  branch  of  the  pulmonary  artery,  and  the 
right  side  of  the  main  trunk  of  it,  in  such  a manner  that 
it  proceeds  downwards  between  the  two  branches  and 
behind  the  angle  formed  by  their  bifurcation.  From  this 
place  of  bifurcation  a short  ligament  proceeds  to  the  lower 
part  of  the  curve  of  the  aorta,  which  is  almost  in  contact 
with  it.  This  ligament  was  originally  the  canal  that  formed 


* See  page  59  of  this  volume. 


Pulmonary  Vessels . 309 

the  communication  between  the  pulmonary  artery  and  the 
aorta  of  the  foetus.*  Each  of  the  great  branches  of  the 
pulmonary  artery  takes  a direction  backwards,  and  to  its 
respective  side.  It  soons  joins  the  corresponding  branch 
of  the  trachea  and  the  two  pulmonary  veins,  being  ante- 
rior to  the  branch  of  the  trachea,  and  above  the  pulmonary 
veins.  It  is  also  invested,  in  common  with  them,  by  that 
portion  of  the  pleura  which  forms  the  mediastinum,  and 
thus  enters  into  the  composition  of  the  root  of  the  lungs. 

The  pulmonary  veins  are  four  in  number — two  on 
each  side.  In  conformity  to  the  mode  of  description  which 
we  have  adopted,  it  may  be  said  that  they  arise  from  the 
sides  of  the  Left  Auricle , and  proceed  nearly  in  a trans- 
verse direction,  two  of  them  to  each  lung;  where  they  ac- 
company the  branches  of  the  artery  and  of  the  trachea, 
being  invested  by  the  mediastinum  in  common  with  these 
branches.  It  has  been  observed,  that  they  differ  from  veins 
in  general,  by  preserving  a diameter  nearly  similar  to  that 
of  the  arteries  which  they  accompany. 


* See  page  68. 


SYSTEM  OF  ANATOMY. 


PART  X. 


OF  THE  NERVES. 

The  nerves  are  those  whitish  cords  which  pass  from 
the  brain  and  spinal  marrow  to  the  various  parts  of  the 
body. 

A general  account  of  their  origin  is  contained  in  the 
description  of  the  basis  of  the  brain  and  of  the  spinal 
marrow,*  which  may  be  considered  as  introductory  to 
the  present  subject. 

The  nerves,  in  general,  appear  to  be  bundles  or  fasci- 
culi of  small  cords,  each  of  which  is  composed  of  a series 
of  fibres  that  are  still  smaller.  These  fibres  consist  of  me- 
dullary matter,  which  is  derived  from  the  brain  and  spinal 
marrow,  and  is  inclosed  in  a membranous  sheath  that  ap- 
pears to  arise  from  the  pia  mater.  The  smaller  the  fibre, 
the  more  delicate  is  the  membrane  which  invests  it. 

As  the  nerves  proceed  from  the  brain  and  spinal  mar- 
row, through  the  foramina  of  the  cranium  and  the  spine, 
they  are  inclosed  in  a sheath  formed  by  the  dura  mater; 
but  when  they  arrive  at  the  exterior  extremity  of  the  fo- 
ramina in  those  bones,  this  coat,  derived  from  the  dura 
mater,  appears  to  separate  into  two  laminae.  The  exterior 
lamina  combines  with  the  periosteum,  and  the  interior 


*See  volume  I.  page  321. 


311 


General  Structure  of  the  Nerves. 

continues  to  invest  the  nerve,  but  seems  to  change  im- 
mediately into  cellular  substance;  so  that  the  exterior  coat 
of  the  nerves  may  be  regarded  as  composed  of  cellular 
membrane,  which  is  continued  from  the  sheath  derived 
from  the  dura  mater. 

It  has  been  supposed  that  the  membrane  which  forms 
the  sheaths  for  the  medullary  fibrils,  of  which  the  nerves 
are  composed,  is  of  a peculiar  nature;  but  it  appears  to  be 
derived  from  the  pia  mater,  investing  the  brain  and  the 
spinal  marrow.  It  is  very  vascular.* 

The  ramification  of  a nerve  is  simply  the  separation  of 
some  fibres  from  the  general  fasciculus.  The  branch  com- 
monly forms  an  acute  angle  with  the  main  trunk. 

The  course  of  these  branches,  from  their  origin  to  their 
termination,  is  generally  as  straight  as  possible. 

When  the  nervous  cords  are  examined  in  an  animal 
recently  dead,  there  is  an  appearance  of  white  lines  ar- 
ranged in  a transverse  or  spiral  direction.  The  cause  of 
this  appearance  is  not  well  understood. 

In  various  parts  of  the  body  networks  are  formed  by 
the  combination  of  different  nerves,  or  the  branches  of 
nerves.  In  those  instances  the  branches  of  one  nerve  unite 
with  those  of  another,  and  form  new  branches.  These  new 
branches  again  divide,  and  their  ramifications  unite  with 
other  new  ramifications  to  form  other  new  trunks.  These 
new  trunks  divide  again,  and  form  new  combinations  in 
the  same  way. 

The  trunks  last  formed  proceed  to  the  different  parts  of 

* Several  authors  have  written  professedly  on  the  structure  of  the 
nerves,  viz.  Monro,  in  his  “ Observations  on  the  Structure  and  Func- 
tions of  the  Nervous  System.” — Bichat,  “ Anatomie  Generale.” — 
Fontana,  “ Treatise  on  the  Poison  of  the  Viper.” — Reil,  “ Exercita- 
- liones  Anatomicae.” — Scarpa,  “ Annotationes  Academicae.” — Pro- 
chaska,  “ De  Structura  Nervorum.” 

I regret  that  it  has  not  been  in  my  power  to  procure  Reil,  Pro- 
chaska,  or  Scarpa. 


312 


Plexuses . — Ganglions. 

the  body,  as  other  nerves  do  which  arise  immediately 
from  the  brain. 

These  combinations  are  denominated  Plexuses.  There 
are  several  of  them  in  the  cavities  of  the  abdomen  and 
thorax,  formed  by  the  ramifications  of  the  par  vagum  and 
the  sympathetic  nerves.  The  four  lower  cervical  and  the 
first  dorsal  nerve  form  a very  remarkable  plexus  of  this 
kind,  which  extends  from  the  side  of  the  neck  to  the 
axilla,  and  forms  the  nerves  of  the  arm.  The  lumbar 
nerves  form  a similar  plexus,  although  not  so  complex, 
from  which  the  crural  nerve  arises.  The  anterior  nerves 
of  the  sacrum  also  unite  for  the  formation  of  the  great 
sciatic  nerve. 

It  appears  to  be  clearly  ascertained,  that  the  great 
object  of  this  peculiar  arrangement  is  the  combination  of 
nervous  fibres  from  many  different  sources,  in  each  of 
the  nerves,  which  are  distributed  to  any  organ.  Thus,  the 
smaller  nerves  of  the  arm  that  are  distributed  to  the  dif- 
ferent parts,  are  not  to  be  regarded  simply  as  branches 
of  any  one  of  the  five  nerves  which  are  appropriated  to 
the  upper  extremity,  but  as  composed  of  fibres  which  are 
derived  from  each  of  them. 

Many  of  the  nerves  are  enlarged  in  particular  places, 
so  as  to  form  small  circumscribed  tumours,  which  are 
denominated  Ganglions. 

These  Ganglions  are  generally  of  a reddish  colour.  By 
very  dextrous  management,  they  can  be  shown. to  consist 
of  a texture  of  fibres.  The  larger  cords,  which  compose 
the  nerve,  seem  suddenly  to  be  resolved  into  the  small 
fibres,  of  which  they  consist.  These  small  fibres,  after 
proceeding  separately  a greater  or  lesser  distance,  accord- 
ing to  the.  size  of  the  ganglion,  and  changing  their  relative 
situation,  are  again  combined  in  cords  which  recompose 
the  nerve. 

These  fibres  appear  to  be  surrounded  by  a fine  cellular 
substance,  which  is  vascular,  moist  and  soft.  It  is  assert. 


Structure  of  Ganglions.  313 

ed  that,  in  fat  subjects,  an  oily  substance,  resembling  fat; 
and  in  hydropic  subjects,  a serous  fluid  has  been  found 
in  this  texture. 

Ganglions  are  often  connected  with  but  one  nerve, 
which  seems  to  enter  at  one  extremity  and  go  out  at  the 
other.  But  they  frequently  receive  additional  branches 
from  other  nerves,  and  send  off  additional  branches  to 
parts  different  from  those  to  which  their  principal  nerves 
are  directed.  When  connected  with  but  one  nerve,  they 
have  been  called  simple  ganglions:  when  they  receive  and 
give  off  additional  branches,  they  are  denominated  com- 
pound ganglions . — It  does  not  appear  that  there  is  any  im- 
portant difference  in  their  structure  in  these  cases. 

The  simple  ganglions  occur  in  the  nerves  of  the  spinal 
marrow — the  posterior  fasciculus  of  the  nerves  having 
always  formed  a ganglion  before  it  is  joined  by  the  ante- 
rior fasciculus.  The  sympathetic  nerve,  throughout  its 
whole  extent,  forms  compound  ganglions. 

The  use  of  this  particular  structure  does  not  appear  to 
be  perfectly  known.  It  seems,  however,  certain,  that  the 
different  fibres — (of  which  the  nerves  forming  ganglions 
are  composed) — are  blended  together  and  arranged  in  a 
manner  different  from  that  in  which  they  were  arranged 
before  the  nerve  entered  the  ganglion. 

It  ought  to  be  observed,  that  the  combination  of 
nervous  fibrillae,  so  as  to  bring  together  those  fibrils  which 
originally  belonged  to  different  cords,  seems  to  have  been 
kept  in  view  throughout  the  whole  arrangement  of  the  ner- 
vous system.  It  is  not  only  in  the  plexus  and  the  ganglion 
that  this  appears,  but  also  in  some  of  the  larger  nerves;  for 
in  them,  the  fibres  which  form  the  cords  that  compose  the 
nerve,  instead  of  running  parallel  to  each  other,  along  the 
whole  extent  of  the  nerve,  form  a species  of  plexus  in 
their  course;  separating  from  the  fibres  with  which  they 
Vol.  II.  2 K 


314 


Reproduction  of  Nerves. 

were  originally  combined,  and  uniting  with  the  fibres  of 
other  cords;  as  in  other  cases  of  plexus.* 

There  have  been  doubts  respecting  the  possibility  of  a 
reproduction  of  the  substance  of  the  nerves  when  it  has 
been  destroyed;  but  it  appears  to  have  been  clearly  proved 
by  the  experiments  of  Mr.  Haighton,  that  a reproduction 
does  really  take  place. f 

Nine  pair  of  nerves  proceed  from  the  brain  through 
the  foramina  of  the  cranium.  They  are  called  Nerves  of 
the  Brain , or  Cerebral  Nerves.  One  pair  pass  off  between 
the  cranium  and  the  spine,  which  are  called  Sub ■ Occipital . 
Twenty-nine  or  thirty  pair  pass  through  the  foramina  of 
the  spine:  they  are  denominated  Cervical , Dorsal , Lumbai' 
and  Sacral , from  the  bones  with  which  they  are  respec- 
tively connected.  There  are  seven  pair  of  Cervical  nerves, 
twelve  Dorsal,  five  Lumbar,  and  five  or  six  Sacral — 
amounting,  with  the  nerves  of  the  brain,  to  thirty- nine  or 
forty  pair. 

NERVES  OF  THE  BRAIN. 

The  nerves  which  go  off  from  the  brain  and  medulla 
oblongata  are  named  numerically,  according  to  the  order 
in  which  they  occur;  beginning  with  the  anterior.  They 
also  have  other  names,  which  generally  are  expressive  of 
the  functions  of  the  different  parts  to  which  they  are  dis- 
tributed. 

Those  which  go  to  the  nose  are  anterior  to  all  the  others, 
and  are  therefore  denominated 

* See  Monro’s  Observations  on  the  Structure  and  Functions  of  the 
Nervous  System.  Plate  xviii. 

t See  London  Philosophical  Transactions,  for  1795,  Part  I. 


Olfactory  Nerves. 


315 


THE  FIRST  PAIR,  OR  THE  OLFACTORY  NERVES. 

They  arise  by  three  delicate  white  fibres  from  the  under 
and  posterior  part  of  the  anterior  lobes  of  the  brain,  being 
derived  from  the  Corpora  Striata.  They  proceed  forward 
to  the  depression  on  the  cribriform  plate  of  the  ethmoid 
bone,  on  each  side  of  the  crista  galli.  The  upper  surface 
occupies  a small  sulcus  formed  by  the  convolutions  of 
the  lower  surface  of  the  brain,  and,  therefore,  has  a lon- 
gitudinal ridge  on  it.  The  lower  surface  is  flat.  Their 
texture  is  like  that  of  the  medullary  part  of  the  brain. 

On  each  side  of  the  crista  galli  each  of  them  forms 
a pulpy  enlargement  of  a brownish  colour,  which  is  called 
the  bulb,  and  has  been  considered  as  a ganglion. 

From  this  bulb  many  fine  and  delicate  cords  go  off, 
which  proceed  through  the  dura  mater  and  the  foramina 
of  the  cribriform  plate  to  the  Schneiderian  membrane. — 
These  ramifications  of  the  olfactory  nerve  seem  to  receive 
a coat  from  the  dura  mater,  as  they  are  much  more  firm 
after  they  have  passed  through  it.  They  appear  to  be 
arranged  in  two  rows  as  they  proceed  from  the  ethmoid 
bone — one  running  near  to  the  septum,  and  the  other  to 
the  opposite  surface  of  the  ethmoid  bone.* 

THE  SECOND  PAIR,  OR  THE  OPTIC  NERVES, 

Originate  from  the  Thalami  Nervorum  Opticorum , and 
appear  on  the  external  and  lower  surface  of  the  brain,  on 
each  side  of  the  sella  turcica. 

Each  of  them  seems  like  a cord  of  medullary  matter, 
inclosed  in  a coat  derived  from  the  pia  mater,  and  has 
not  the  fasciculated  appearance  of  the  other  nerves.  The 
medullary  matter,  however,  appears  to  be  divided  by 


* See  Vol.  II.  Page  6. 


316 


Second  and  Third  Pair  of  Nerves. 

processes  that  pass  through  it,  which  are  derived  from 
the  coat  of  the  nerve. 

They  proceed  obliquely  forward  and  inward,  on  each 
side  of  the  sella  turcica,  in  contact  with  the  brownish 
cineritious  substance,  in  which  the  infundibulum  and  the 
corpora  albicantia  of  Willis  are  situated.*  Anterior  to 
this  substance  they  come  in  contact  with  each  other,  and 
again  separate,  in  such  a way,  that  it  is  an  undecided 
question  whether  they  decussate  each  other,  or  whether 
each  forms  an  angle,  and  is  in  contact  with  the  other  at 
the  angle. 

From  this  place  of  contact,  each  nerve  proceeds  to  its 
respective  foramen  opticum,  where  it  receives  a coat  from 
the  dura  mater,  which  extends  with  it  to  the  eye,  as  has 
been  described  in  the  account  of  that  organ. 

THE  THIRD  PAIR  OF  NERVES 

Are  sometimes  called  Motores  Oculorum , in  consequence 
of  their  distribution  to  several  muscles  of  the  eye.  They 
arise  at  the  inside  of  the  crura  cerebri,  and  make  their  ap- 
pearance on  the  basis  of  the  brain,  at  the  anterior  part  of 
the  pons  Varolii. 

They  originate  by  numerous  threads,  which  soon  unite 
so  as  to  form  a cord  that  passes  through  the  dura  mater, 
on  each  side  of  the  posterior  clinoid  process,  and  continues 
through  the  cavernous  sinus,  and  the  foramen  Iacerum,  to 
the  orbit  of  the  eye. 

Before  this  nerve  enters  the  orbit  it  generally  divides 
into  two  branches,  which  are  situated  one  above  the  other. 
The  Uppermost  Branch'is  spent  principally  upon  the  rectus 
superior  muscle  of  the  eye,  but  sends  a twig  to  the  levator 
palpebras.  The  Inferior  Branch  is  distributed  to  two  of  the 
recti  muscles,  viz.  the  internus  and  the  inferior,  and  also 


* See  Vol.  I.  p.  323. 


317 


Fourth  and  Fifth  Pair  of  Nerves. 

to  the  inferior  oblique.  It  likewise  sends  a twig  to  a 
small  ganglion  in  the  orbit,  called  the  Lenticular  or 
Ophthalmic  Ganglion  * from  which  proceed  the  fine  nerv- 
ous fibres  that  perforate  the  sclerotica  eoat.f 

THE  FOURTH  PAIR  OF  NERVES 

Are  called  the  Pathetic , in  consequence  of  the  expression 
of  the  countenance  produced  by  the  action  of  the  muscle 
on  which  they  are  spent.  They  arise  from  the  side  of  the 
valve  of  the  brain,  below  and  behind  the  Tubercula  Qua- 
drigeminal and  are  so  small  that  they  appear  like  sewing 
thread.  They  proceed  round  the  crura  of  the  cerebrum, 
and  appear  on  the  surface  between  the  pons  Varolii  and 
the  middle  lobes  of  the  brain.  They  proceed  along  the 
edge  of  the  tentorium  which  they  perforate,  and  passing 
through  the  upper  part  of  the  cavernous  sinus,  enter  the 
orbit  by  the  foramina  lacera.  They  are  exclusively  appro- 
priated to  the  Superior  Oblique  or  Trochlearis  muscle. 


THE  FIFTH  PAIR  OF  NERVES 

Are  called  Trigemina , because  each  nerve  divides  into 
three  great  branches. 

These  nerves  arise  from  the  crura  of  the  cerebellum 
where  they  unite  to  the  pons  Varolii,  by  distinct  fibres, 
which  are  connected  so  as  to  form  a cord  or  nerve,  that  i$ 
larger  than  any  other  nerve  of  the  brain.  In  many  subjects 
this  cord  seems  partially  divided  into  two  portions,  the 
anterior  of  which  is  much  smaller  than  the  posterior,  and 
appears  softer  at  its  origin. 

•This  ganglion,  which  is  considered  as  the  smallest  in  the  body, 
lies  on  the  outside  of  the  optic  nerve,  near  its  entrance  into  the  orbit, 
and  is  generally  surrounded  by  soft  adipose  matter 

t See  Volume  I.  page  342. 

4 Ibid.  Page  324 


318 


First  Branch  of  the  Fifth  Pair. 

It  passes  into  a short  canal  formed  by  the  dura  mater, 
near  the  anterior  extremity  of  the  petrous  portion  of  the 
temporal  bone,  at  a small  distance  below  the  edge  of  the 
tentorium.  It  is  perfectly  loose  and  free  from  adhesion  to 
the  surface  of  this  canal;  but  it  soon  passes  out  of  it  under 
the  dura  mater,  and  then  adheres  to  that  membrane. 
After  leaving  the  canal  it  expands  like  a fan,  but  still 
consists  of  fine  fibres  which  have  some  firmness.  It  is 
said  that  there  are  seventy  or  eighty  of  these  fibres  in  the 
expansion,  but  they  appear  to  be  more  numerous.  Round 
the  circumference  of  the  expansion  is  a substance  of  a 
brownish  colour,  into  which  the  fibres  enter.  This  is  the 
Semilunar  Ganglion , or  the  Glangion  of  Gasser,  and  from 
it  the  three  nerves  go  off. 

These  nerves  pass  off  from  the  convex  side  of  the 
Ganglion,  and  are  denominated  the  Ophthalmic , the  Su- 
perior Maxillary,  and  the  Inferior  Maxillary. 

The  Ophthalmic  Nerve 

Passes  into  the  orbit  of  the  eye  through  the  foramen 
lacerum:  it  there  divides  into  several  branches,  which  are 
called,  from  their  distribution,  the  Frontal  or  Supra- 
Orbitar,  the  Nasal  and  the  Lachrymal. 

The  Frontal  or  Supra-  Orbitar  branch  proceeds  forward 
in  the  upper  part  of  the  orbit,  exterior  to  the  membrane 
which  lines  it,  and  divides  into  two  ramifications.  One  of 
these  is  small,  and  passes  out  of  the  orbit  near  the  pulley 
of  the  superior  oblique,  to  be  spent  upon  the  orbicularis 
muscle  and  the  contiguous  parts. 

The  other  ramification  passes  through  the  Supra-Qrbi- 
tary  Foramen,  or  through  the  notch,  which  is  in  the  place 
of  that  foramen,  and  divides  into  a number  of  twigs,  some 
of  which  pass  transversely  towards  the  side  of  the  head, 
and  communicate  with  twigs  from  the  portio  dura.  Most 
of  the  others  extend  upwards  on  the  head.  Some  are  dis- 


.319 


Second  Branch  of  the  Fifth  Pair. 

• 

tributed  to  the  anterior  part  of  the  occipito  frontalis  mus- 
cle, and  the  integuments  of  the  forehead;  others  are  spent 
upon  the  upper  portion  of  the  scalp.  Some  of  the  extreme 
parts  of  these  ramifications  also  communicate  with  the 
portio  dura. 

The  Nasal  Branch  proceeds  obliquely  forward  towards 
the  inner  side  of  the  orbit,  and  sends  a twig  in  its  course 
to  the  lenticular  ganglion.  It  also  sends  off  some  small 
twigs,  to  join  the  ciliary  nerves  which  go  from  the  gang- 
lion. On  the  inside  of  the  orbit  a branch  leaves  it,  which 
proceeds  through  the  Foramen  Orbitare  Internum  Anterius 
to  the  cavity  of  the  cranium,  and  passes  a small  distance 
upon  the  cribriform  plate  of  the  ethmoid  bone,  under  the 
dura  mater,  to  a fissure  in  the  said  plate  near  the  crista 
galli,  through  which  it  proceeds  into  the  cavity  of  the 
nose.  Here  it  divides  into  twigs,  some  of  which  pass  on 
the  septum  near  its  anterior  edge,  and  terminate  on  the 
integuments  at  the  end  of  the  nose,  while  others  pass 
down  on  the  inferior  turbinated  bone. 

After  parting  with  the  ramification  to  the  nose,  the 
remainder  of  the  nasal  branch  continues  to  the  internal 
canthus  of  the  eye,  and  sends  twigs  to  the  lachrymal  sac, 
the  caruncula  lachrymalis,  the  eye-lids,  and  the  exterior 
surface  of  the  upper  part  of  the  nose. 

The  Lachrymal  Branch  proceeds  obliquely  forward 
and  outwards,  towards  the  lachrymal  gland.  In  its  course 
it  sends  off  a twig  which  passes  through  the  spheno 
maxillary  fissure,  and  communicates  with  a twig  of  the 
upper  maxilLary  nerve,  and  one  or  more  twigs  that  pass  to 
foramina  in  the  molar  bone.  The  main  branch  passes  to 
the  lachrymal  gland,  and  some  twigs  Continue  beyond  it 
to  the  contiguous  parts. 

The  Superior  Maxillary  Nerve. 

The  second  branch  of  the  fifth  pair  is  examined  with 
great  difficulty^  on  account  of  its  peculiar  situation.  It 


320  Second  Branch  of  the  Fifth  Pair:  or 

proceeds  from  the  semilunar  ganglion,  and  passes  through 
the  foramen  rotundum  of  the  sphenoid  bone  into  the 
upper  part  of  the  zygomatic  fossa.  In  this  situation  it 
sends  a twig  to  the  orbit  by  the  spheno  maxillary  fissure, 
and  a branch,  called  the  Infra  Orbitar , which  appears  like 
the  main  nerve,  as  it  preserves  a similar  direction,  to  the 
infra  orbitar  canal.  At  the  same  place  it  sends  downwards 
two  branches  which  unite  together  almost  immediately 
after  their  origin,  and,  as  soon  as  they  have  united,  enlarge 
into  a ganglion.*  This  glangion  is  called  the  Spheno- 
Palatine.  It  is  rather  of  a triangular  figure,  and  lies  very 
near  the  spheno-palatine  foramen.  It  gives  off  a posterior 
branch,  which  passes  through  the  pterygoid  foramen  to 
the  cavity  of  the  cranium:  some  branches  which  proceed 
through  the  spheno-palatine  foramen  to  the  nose,  and  are 
called  the  Spheno- Palatine  or,  Lateral  Nasal  Nerves:  and 
an  inferior  branch,  that  proceeds  through  the  posterior 
palatine  canal,  and  is  called  the  Palatine  Nerve. 

The  small  branch,  which  was  first  mentioned,  as  going 
to  the  orbit  by  the  spheno  maxillary  fissure,  divides  into 
two  ramifications.  One  of  them  unites  with  a twig  of  the 
lachrymal  branch  above  mentioned,  and  passes  out  of  the 
orbit,  through  a foramen  in  the  molar  bone,  to  the  face;  , 
where  it  is  distributed.  The  other  passes  also  through  a 
foramen  of  the  molar  bone,  into  the  temporal  fossa,  and, 
after  uniting  with  twigs  from  the  Inferior  Maxillary 
Arerve,  proceeds  backwards  and  perforates  the  aponeurosis 
of  the  temporal  muscle,  to  terminate  on  the  integuments 
of  the  temporal  region. 

Before  the  Infra  Orbitar  branch  enters  the  canal  of  that 
name,  it  sends  off  two  twigs,  called  Posterior  Dental 
Nerves , which  pass  downwards  on  the  tuberosity  of  the 
upper  maxillary  bone,  and  enter  into  small  canals  in  that 
bone,  that  are  situated  behind  the  Antrum  Maxillare. 

* Sometimes  a single  branch  passes  downwards  instead  ol  two;  but 
it  forms  a ganglioo  in  the  same  place. 


321 


Superior  Maxillary  Nerve. 

They  subdivide  into  fine  twigs  that  proceed  forward  to  the 
alveoli  of  three  or  four  of  the  last  molar  teeth;  and  pene- 
trate each  of  the  roots  by  a cavity  at  its  extremity.  Twigs 
also  proceed  from  these  nerves  to  the  posterior  part  of  the 
gums  and  the  buccinator  muscle. 

After  the  posterior  dental  nerves  have  left  it,  the  Infra 
Orbitar  nerve  proceeds  forwards  in  the  canal  of  that  name; 
and  near  the  extremity  of  it,  gives  off  the  anterior  dental 
nerve,  which  accompanies  it  for  some  distance,  and  then 
proceeds  downwards  in  a canal  in  the  bone  anterior  to 
the  antrum  maxillare.  In  its  course  this  nerve  divides 
into  many  fibres,  which  pass  to  the  roots  of  the  incisor, 
canine,  and  small  molar  teeth,  each  in  its  proper  canal. 
These  dental  branches  sometimes  pass  in  the  antrum 
maxillare  between  the  lining  membrane  and  the  bones. 
The  Infra  Orbitar  nerve  passes  out  of  the  foramen  upon 
the  cheek,  and  divides  intb  several  branches  of  considera- 
ble size,  which  are  distributed  on  the  face  from  the  side  of 
the  nose  to  the  back  of  the  cheek,  and  also  upon  the  under 
eye-lid  and  the  upper  lip. 

The  Pterygoid  Nerve,  or  posterior  branch,  passes 
backwards,  from  the  ganglion  to  a canal  in  the  base  of  the 
pterygoid  process  of  the  Os  Sphenoides,  and  proceeds 
through  it.  After  leaving  this  canal,  it  passes  through  a 
substance  almost  as  firm  as  cartilage,  which  closes  the  an- 
terior foramen  lacerum,  at  the  basis  of  the  cranium;  and 
divides  into  two  branches.  The  smallest  of  them,  called 
the  Vidian  Nerve , proceeds  with  a small  artery  to  the 
small  foramen,  or  Hiatus  Fallopii,  on  the  anterior  side  of 
the  petrous  portion  of  the  temporal  bone,  and  continues, 
through  a small  canal,  to  join  the  Portio  Dura  of  the 
seventh  pair  in  the  larger  canal,  called  the  Aqueduct  of 
Fallopius , at  the  first  turn  in  that  canal.*  The  other  branch 

* The  late  Mr.  John  Hunter  believed  that  this  nerve  parts  from 
the  portio  dura  at  the  lower  end  of  the  aqueduct,  and  is  the  corda 
tympani. 

Vol.  II.  2 S 


322  Superior  Maxillary  Nerve. 

of  the  pterygoid  nerve  proceeds  to  the  Foramen  Caro- 
ticum,  and  passes  through  it,  with  a twig  of  the  sixth 
pair,  to  join  the  first  cervical  ganglion  of  the  Intercostal 
Nerve. 

The  Spheno- Palatine,  or  Lateral  Nasal  Nerves,  consist 
of  several  branches  which  pass  from  the  spheno-palatine 
ganglion,  through  the  spheno-palatine  foramen,  into  the 
nose.  Some  of  them  are  distributed  to  that  part  of  the 
pituitary  membrane,  which  is  above  the  upper  meatus, 
and  others  to  the  part  which  is  immediately  below  it. 
Some  of  the  branches  which  thus  enter  the  nose  are  spread 
upon  the  septum:  one  among  them  extends  upon  it,  down- 
wards and  forwards,  to  the  anterior  part  of  the  palatine 
process  of  the  upper  maxillary  bone,  where  it  enters  into 
the  foramen  incisivum,  and  terminates  in  a papilla  in  the 
roof  the  mouth.* 

The  Palatine  Branch  proceeds,  through  the  canal  form- 
ed by  the  upper  maxillary  and  palate  bones,  to  the  roof 
of  the  mouth  and  the  soft  palate.  Soon  after  its  origin,  it 
sends  off  a twig  which  proceeds  down  a small  canal  that 
is  behind  it.  It  also  sends  off,  as  it  proceeds  downwards, 
several  twigs  to  that  part  of  the  membrane  of  the  nose 
which  covers  the  inferior  turbinated  bone.  When  it  ar- 
rives at  the  roof  of  the  mouth,  it  divides  into  several 
branches  which  run  forwards,  and  are  distributed  to  the 
membrane  which  lines  the  roof  of  the  mouth.  Some  of  its 
branches  pass  to  the  soft  palate,  the  uvula,  and  the  tonsils; 
small  filaments  pass  into  the  back  part  of  the  upper  jaw. 

*The  curious  distribution  of  this  nerve  appears  to  have  been 
known  to  the  late  John  Hunter,  and  also  to  Cotunnius;  but  it  is  mi- 
nutely described  by  Scarpa,  and  is  delineated  by  Soemmering  in  his 
plate  of  the  nose. — See  “ Observations  on  certain  parts  of  the  Animal 
Economy,”  by  J.  Hunter,  page  219, — and  also  Scarpa  “ De  Organo 
Olfactus.”  in  this  last  are  some  interesting  observations  relative  to 
the  ducts  of  Stcno. 


Third  Branch  of  the  Fifth  Pair . 


323 


The  Inferior  Maxillary  Nerve,  or  the  Third  Branch  of 
the  Fifth  Pair , 

Passes  through  the  foramen  ovale  into  the  zygomatic 
fossa,  and  divides  into  two  branches , one  of  which  sends 
ramifications  to  many  of  the  contiguous  muscles,  as  the 
Temporal,  the  Masseter,  the  Buccinator,  the  Pterygoid; 
and  also  to  the  anterior  part  of  the  ear  and  the  side  of  the 
head.  The  other  branch  passes  between  the  pterygoid 
muscles,  and  divides  into  two  ramifications,  one  of  which 
proceeds  to  the  tongue,  and  is  called  the  Lingual  ox  Gus- 
tatory, while  the  other  passes  into  the  canal  of  the  lower 
jaw. 

The  Lingual  Nerve  proceeds  between  the  pterygoid 
muscles,  and  in  its  course  is  joined  by  the  chorda  tym- 
pani.  It  continues  forward  between  the  maxillary  gland 
and  the  lining  membrane  of  the  mouth;  and  passes  near 
the  excretory  duct  of  that  gland,  above  the  mylo-hyoideus 
and  the  sublingual  gland,  to  the  under  side  of  the  tongue, 
near  the  point:  it  then  divides  into  a number  of  branches 
which  enter  into  that  body  between  the  genio  hyoideus 
and  lingualis  muscles. — This  nerve  has  been  supposed  to 
be  particularly  concerned  in  the  function  of  taste,  because 
many  of  its  branches  continue  to  the  upper  surface  of  the 
tongue,  especially  near  the  point.  In  its  course  it  has  a 
communication  with  the  ninth  pair  of  nerves,  and  it  sends 
twigs  to  the  membrane  of  the  mouth  and  gums,  and  the 
contiguous  parts. 

After  parting  with  the  lingual  nerve,  the  inferior  max- 
illary continues  to  the  upper  and  posterior  orifice  of  the 
canal  in  the  lower  jaw.  Before  it  enters  this  canal  it  sends 
a branch  to  the  sub-maxillary  gland,  and  to  the  muscles 
under  the  jaw.  It  then  enters  the  canal,  attended  by  blood- 
vessels, and  proceeds  along  it  to  the  anterior  maxillary 
foramen,  on  the  side  of  the  chin,  through  which  it  passes 


324 


Sixth  and  Seventh  Pair  of  Nerves. 

out.  In  this  course  it  sends  twigs  to  the  sockets  of  the 
teeth,  and  generally  supplies  all  the  large  and  one  of  tlie 
small  grinders.  Before  it  leaves  the  jaw  it  sends  a branch 
forwards,  which  supplies  the  Remaining  teeth  on  the  side 
to  which  it  belongs.  After  passing  out,  through  the  ante- 
rior foramen,  it  is  spent  upon  the  muscles  and  integuments 
of  the  front  of  the  cheek,  the  chin,  and  the  under  lip. 

THE  SIXTH  FAIR  OF  NERVES 

Are  called  Motores  Externi.  They  arise  from  the  com- 
mencement of  the  medulla  oblongata,  and  proceed  for- 
ward under  the  pons  Varolii.  They  proceed  through  the 
dura  mater  on  the  inside  of  the  fifth  pair,  and  appear  to 
pass  through  the  cavernous  sinuses,  but  are  inclosed  in 
sheaths  of  cellular  membrane  while  they  are  in  those 
sinuses.  When  in  this  situation  they  are  near  the  carotid 
arteries,  and  each  nerve  sends  off  one  or  more  very  fine 
twigs,  which  being  joined  by  a twig  from  the  pterygoid 
branch  of  the  fifth  pair,  accompany  the  carotid  artery 
through  the  carotid  canal,  and  then  unite  themselves  to 
the  upper  extremity  of  the  upper  cervical  ganglion  of  the 
intercostal  nerve. 

The  sixth  pair  afterwards  pass  into  the  orbit  of  the  eye, 
each  through  the  foramen  lacerum  of  its  respective  side, 
and  is  spent  upon  the  Rectus  Externus  or  Abductor  mus. 
cle  of  the  eye. 

THE  SEVENTH  FAIR  OF  NERVES 

Comprises  two  distinct  cords  which  have  very  different 
destinations;  and  have,  therefore,  been  considered  as  dif- 
ferent nerves,  by  several  anatomists.  One  of  these  cords 
is  appropriated  to  the  interior  of  the  ear,  and  is  the  proper 
Auditory  Nerve.  The  other  is  principally  spent  upon  the 
face,  and,  therefore,  has  been  called  the  Facial.  They 
have,  however,  more  frequently  been  denominated  the 
Seventh  Pair , and  distinguished  from  each  other,  in  con- 


t 


Composition  of  the  Seventh  Pair. — Portio  Dura.  325 

sequence  of  a great  difference  in  their  texture,  by  the 
appellations  of  Portio  Dura  and  Portio  Mollis. 

These  two  cords  pass  off  nearly  in  contact  with  each 
other,  from  the  side  of  the  upper  part  of  the  Medulla  Ob- 
longata, where  it  is  in  contact  with  the  pons  Varolii;  but 
the  Portio  Mollis  can  be  traced  to  the  fourth  ventricle, 
while  the  Portio  Dura  is  seen  to  arise  from  the  union  of 
the  pons  Varolii  with  the  medulla  oblongata  and  the  crura 
Cerebelli.  The  Portia  Dura , at  its  origin,  is  on  the  inside 
of  the  Portio  Mollis. — Between  these  cords  are  one  or 
more  small  fibres,  called  Portio  Media,  which  seem  to 
originate  very  near  them,  and  finally  unite  with  the  Portio 
Dura. 

Each  of  the  seventh  pair  of  nerves,  thus  composed, 
proceeds  from  its  origin,  to  the  Meatus  Auditorius  In- 
ternus  of  the  temporal  bone;  and  the  Portio  Mollis  divides 
into  fasciculi,  which  proceed  to  the  different  parts  of  the 
organ  of  hearing,  in  the  manner  described  in  the  account 
of  the  ear.* 

The  Portia  Dura  enters  an  orifice  at  the  upper  and 
anterior  part  of  the  end  or  bottom  of  the  Meatus  Audito- 
rius Internus.  This  orifice  is  the  commencement  of  a 
Canal,  which  has  been  called  the  Aqueduct  of  Fallopius , 
and  proceeds  from  the  Meatus  Auditorius  Internus  to  the 
external  foramen,  between  the  mastoid  and  stiloid  pro- 
cesses at  the  basis  of  the  cranium.  This  canal  first  curves 
backwards  and  outwards,  near  to  the  upper  surface  of  the 
petrous  bone,  then  forms  an  acute  angle,  and  proceeds 
(backwards  and  downwards)  to  the  stilo-mastoid  fora- 
men, passing  very  near  the  cavity  of  the  tympanum  in  its 
course. 

The  Portio  Dura,  as  it  passes  into  the  canal  from  the 
meatus  internus,  seems  to  receive  an  investment  from  the 
dura  mater.  It  fills  up  the  canal,  but  does  not  appear  to  be 


* See  Volume  I,  page  380. 


326  Chorda  Tympani. — Pcs  Atiserinus. 

compressed.  Near  the  angle  it  is  joined  by  the  twig  of 
the  vidian  nerve,  which  proceeds  from  the  pterygoid 
branch  of  the  fifth  pair,  and  enters  the  petrous  bone  by  the 
small  foramen  innominatum  on  its  anterior  surface.  In  its 
course  through  the  canal  it  sends  oflf  some  very  small 
twigs  to  the  muscles  and  appurtenances  of  the  small 
bones  of  the  ear,  and  to  the  mastoid  cells;  and,  when 
it  has  arrived  almost  at  the  end  of  the  canal,  it  sends  off, 
in  a retrograde  direction,  a smallbranch  which  proceeds 
into  the  cavity  of  the  tympanum,  (entering  it  by  a foramen 
at  the  base  of  the  pyramid,)  and  crosses  the  upper  part  of 
it,  near  the  membrana  tympani,  between  the  long  pro- 
cesses of  the  Malleus  and  Incus.  This  twig  is  the  Chorda 
Tympani:  it  proceeds  from  the  cavity,  by  a fissure  on  the 
outside  of  the  Eustachian  tube,  to  join  the  lingual  branch 
of  the  fifth  pair,  as  has  been  already  mentioned.* 

The  Portio  Dura , after  passing  out  of  the  Foramen 
Stylo- Mas  toideum,  is  situated  behind  and  within  the  pa- 
rotid gland.  Here  it  gives  small  twigs  to  the  back  of  the 
ear  and  head,  and  to  the  digastric  and  stylo-hvoideus 
muscles.  It  perforates  the  gland  after  sending  filaments 
to  it,  and  then  divides  into  branches  which  arc  arranged 
in  such  a manner  that  they  constitute  what  has  been  called 
the  Pes  Anserinus. 

To  describe  the  various  branches  in  this  expansion 
would  be  more  laborious  than  useful.  Some  of  them 
are  spread  upon  the  temple  and  the  upper  part  of  the 
side  of  the  head,  and  unite  with  the  supra-orbitar  branches 
of  the  ophthalmic  nerve.  Some  pass  above  and  below  the 
eye,  and  are  distributed  to  the  orbicularis  muscle,  and 
communicate  with  nervous  twigs  that  pass  through  fora- 

* The  lateJohn  Hunter  believed  that  the  chorda  tympani  is  mere- 
ly a continuation  of  the  twig  of  the  pterygoid  branch  which  joins  the 
portio  dura  above. — See  Observations  on  certain  parts  of  the  Ani- 
mal Economy,  page  220. 


Composition  of  the  Eighth  Pair  of  Nerves.  327 

mina  in  the  malar  bone,  &c.  Some  large  branches  pass 
transversely.  They  cross  the  masseter  muscle,  and  divide 
into  ramifications  which  are  spent  upon  the  cheek  and  the 
side  of  the  nose  and  lips,  and  communicate  with  the  small 
branches  of  the  superior  maxillary  nerve. 

A large  number  of  branches  pass  downwards.  Many  of 
them  incline  forwards,  and  are  spent  on  the  soft  parts 
about  the  under  jaw;  while  others  proceed  below  the  jaw 
to  the  superficial  muscles  and  integuments  of  the  upper 
part  of  the  neck,  communicating  with  the  branches  of  the 
contiguous  nerves.* 

THE  EIGHTH  PAIR  OF  NERVES 

Are  very  frequently  denominated  the  Par  Fagum,  on 
account  of  their  very  extensive  distribution. 

They  arise  from  those  portions  of  the  medulla  oblon- 
gata which  are  denominated  the  Corpora  Olivaria.  Each 
nerve  consists  of  a cord,  which  is  anterior,  and  called  the 
Glosso- Pharyngeal ; and  of  a considerable  number  of  small 
filaments,  which  arise  separately,  but  unite  and  form 
another  cord,  the  proper  Par  Vagum.  Associated  with 
these  is  a third  cord,  called  the  Spinal,  or  Accessory  Nerve 
of  Willis,  which  originates  in  the  great  canal  of  the  spine, 
and,  passing  up  into  the  cavity  of  the  cranium,  goes  out 
of  it  with  these  nerves  through  the  foramen  lacerum. 

The  two  first  mentioned  nerves  proceed  from  their 
origin  to  the  posterior  foramen  lacerum,  and  passthrough 
it  with  the  Internal  Jugular  vein, — being  separated  from 
the  vein  by  a small  process  of  bone.  They  are  also  separa- 

* A most  minute  and  laborious  description  of  the  nerves  of  the  face 
was  published  by  the  celebrated  Meclde,  in  the  seventh  volume  of 
Memoirs  ot  the  Royal  Academy  of  Sciences  of  Berlin,  for  the  year 
1751,  accompanied  with  a plate,  exhibiting  the  side  of  the  head,  of 
three  times  the  natural  size.  This  is  republished  in  the  Collection 
Academique:  Partie  Etrangere.— Tom.  viii. 


323  Glosso * Pharyngeal  Nerve. — Par  Vagum. 

ted  from  each  other  by  a small  process  of  the  dura  mater. 
In  the  foramen  they  are  very  close  to  each  other;  but  soon 
after  they  have  passed  through  it,  they  separate  and  pro- 
ceed towards  their  different  destinations. 

The  Glosso- Pharyngeal  proceeds  towards  the  tongue, 
between  the  stylo-pharyngeus  and  the  stylo-glossus  mus- 
cles, following  the  course  of  the  last  mentioned  muscle  to 
the  posterior  part  of  the  tongue.  At  the  commencement 
of  its  course  it  receives  a twig  from  the  Portio  Dura  and 
one  also  from  the  Par  Vagum.  It  soon  gives  off  a branch 
which  passes  down  on  the  inside  of  the  common  carotid 
to  the  lower  part  of  the  neck,  where  it  joins  some  twigs 
of  the  intercostal  to  form  the  cardiac  nerves.  Afterwards 
it  sends  off  several  twigs  to  the  muscles  of  the  pharynx 
and  its  internal  membrane,  and  also  some  twigs  which 
unite  with  others  from  the  upper  cervical  ganglion  of  the 
Sympathetic , and  form  a network  that  lies  over  the  anterior 
branches  of  the  external  carotid.  The  Glosso- Pharyngeal 
finally  enters  the  tongue,  at  the  termination  of  the  hyo- 
glossus  muscle;  and  after  sending  branches  to  the  lingu- 
alis,  and  the  various  muscles  inserted  into  the  tongue, 
terminates  in  small  ramifications  that  are  spent  upon  the 
sides  and  middle  of  the  root  of  the  tongue,  and  upon  the 
large  papillae. 

THE  PAR  VAGUM 

Are  slightly  enlarged  after  passing  through  the  foramen 
lacerum.  As  they  descend,  they  adhere  to  the  superior 
ganglion  of  the  intercostal,  and  also  to  the  ninth  pair. 
They  proceed  behind  and  on  the  outside  of  the  carotid, 
and  are  contained  in  the  same  sheath  of  cellular  membrane 
which  incloses  that  artery  and  the  internal  jugular  vein. 
Each  of  these  nerves,  soon  after  it  leaves  the  cranium, 
gives  a twig  to  the  glosso-pharyngeal;  that  soon  after 
it  sends  oft'  a branch  called  the  Pharyngeal , which  unites 


Superior  Laryngeal  Branch  of  the  Par  Vagum.  329 

to  one  from  the  accessory  nerve,  and  to  one  or  more 
from  the  glosso-pharyngeal,  and  proceeds  to  the  middle 
constrictor  of  the  pharynx,  when  it  expands  into  ramifica- 
tions that  form  a plexus  from  which  proceed  a number  of 
small  twigs  that  go  to  the  larynx,  and  some  that  pass  down 
on  the  common  carotid  artery. 

It  then  sends  off,  downward  and  forward,  the  Superior 
Laryngeal  nerve,  which  continues  in  that  direction  behind 
the  carotid  artery,  and  divides  into  an  external  and  inter- 
nal branch. 

The  Internal  Branch , which  is  the  largest,  proceeds 
between  the  os  hyoides  and  the  thyroid  cartilage;  and 
divides  into  numerous  ramifications  which  are  distributed 
to  the  arytenoid  muscles  and  to  the  membrane  which  lines 
the  larynx  and  covers  the  epiglottis.  It  is  said,  that  fine 
twigs  can  be  traced  into  the  foramina,  which  are  to  be 
seen  in  the  cartilage  of  the  epiglottis; — some  ramifications 
can  be  traced  to  the  pharynx; — others  communicate  with 
the  branches  of  the  recurrent  nerve. 

The  External  Branch  sends  twigs  to  the  pharynx,  to 
the  lower  and  inner  part  cf  the  larynx,  and  to  the  thyroid 
gland. 

In  its  course  downwards,  the  great  nerve  sometimes 
sends  off  a twig,  which  unites  with  one  from  the  ninth 
pair  that  passes  to  the  sterno-hyoidei  and  sterno-thyroidei 
muscles. 

It  uniformly  sends  off  one  or  more  twigs,  which  pass 
into  the  thorax  and  combine  with  small  branches  from 
the  sympathetic  or  intercostal  nerve,  to  form  the  Cardiac 
Plexus,  which  sends  nerves  to  the  heart. 

After  entering  the  thorax,  the  right  trunk  of  the  Par 
Vagum  passes  before  the  subclavian  artery;  and  the  left 
trunk  before  the  arch  of  the  aorta;  and  immediately  after 
passing  these  arteries,  each  of  the  nerves  divides  into  an 
anterior  and  posterior  branch. — The  anterior  is  the  con- 
tinuation of  the  Par  Vagum;  the  posterior  is  a nerve  of 
Vol.  II.  2 T 


330  Recurrent  Branch  of  the  Par  Vagum . 

the  Larynx;  which,  form  its  retrograde  course,  is  called 
the  Recurrent  Nerve. 

On  the  leh  side  the  Recurrent  Nerve  winds  backwards 
round  the  aorta,  and  on  the  right  side  round  the  subclavian 
artery,  and  proceeds  upwards,  deeply  seated,  on  the  side 
of  the  trachea,  to  the  Larynx.  Soon  after  its  origin  it 
sends  filaments  to  a ganglion  of  the  sympathetic,  to  the 
cardiac  plexus,  and  to  a pulmonary  plexus  soon  to  be 
mentioned.  In  its  course  upwards  it  sends  twigs  to  the 
trachea  and  the  oesophagus.  It  proceeds  behind  the  thyroid 
gland,  and  sends  twigs  to  that  organ.  At  the  lower  part  of 
the  larynx  it  sends  of  a branch  which  communicates  with 
branches  of  the  superior  laryngeal  nerve.  It  also  divides 
into  branches  which  are  spread  upon  the  posterior  crico- 
arytenoid, and  the  arytenoid  muscles;  and  also  upon  the 
lateral  crico -arytenoid  and  the  thyro-arytenoid  muscles, 
as  well  as  upon  the  membrane  which  lines  the  back  part 
of  the  larynx  and  the  contiguous  surface  of  the  pharynx. 

There  is  a difference  in  the  arrangement  of  the  recur- 
rents on  the  different  sides,  in  consequence  of  one  winding 
round  the  aorta,  while  the  other  winds  round  the  subcla- 
vian artery. 

After  sending  off  the  recurrents,  each  trunk  of  the 
Par  Vaguin  proceeds  behind  the  ramifications  of  the 
trachea;  but  previously  detaches  some  small  branches, 
which  are  joined  by  twigs  from  the  intercostal  and  from 
the  recurrent,  and  form  a plexus  upon  the  anterior  part  of 
the  vessels  going  to  the  lungs.  This  Anterior  Plexus , after 
sending  off  some  minute  branches  to  the  cardiac  nerves 
and  the  pericardium,  transmits  its  branches,  with  the 
bronchia^  and  the  bloodvessels,  into  the  substance  of  the 
lungs. 

Some  of  the  branches  which  proceed  from  the  par 
vagum,  pass  down  on  the  posterior  part  of  the  trachea, 
and  enter  into  the  membrane  which  forms  it,  and  the 


33 1 


Par  Fagum. — Pulmonary  Plexuses . 

mucous  glands  which  are  upon  it;  and  some  pass  to  the 
oesophagus. 

When  the  par  vagum  is  behind  the  great  vessels  of  the 
lungs,  a number  of  branches  go  off  transversely,  and  are 
also  joined  by  some  fibres  from  the  sympathetic.  These 
form  the  Posterior  Pulmonary  Plexus;  the  ramifications 
from  which  proceed  into  the  substance  of  the  lungs,  and 
are  principally  spent  upon  the  ramifications  of  the  bron- 
chise.  It  has  been  said,*  that  the  small  twigs,  into  which 
they  divide,  very  generally  penetrate  into  the  small  rami- 
fications  of  the  bronchias,  and  are  spent  upon  their  internal 
membrane. 

Soon  after  sending  off  the  nerves  of  the  pulmonary 
plexus,  the  Par  Vagum  proceed  downwards  upon  the 
oesophagus;  the  left  nerve  being  situated  anteriorly,  and 
the  right  posteriorly.  Each  of  these  nerves  forms  a plexus 
so  as  nearly  to  surround  the  oesophagus,  as  they  descend 
on  it;  but  the  network  is  thickest  on  the  posterior  side. 
They  pass  through  the  diaphragm  with  the  oesophagus, 
and  unite  again  so  as  to  form  considerable  trunks. 

The  Anterior , which  is  the  smallest,  proceeds  along 
the  lesser  curvature  of  the  stomach  to  the  pylorus.  Some 
of  its  fibres  are  spread  upon  the  anterior  side  of  the 
stomach  and  the  lesser  omentum.  Others  of  them  extend 
to  the  left  hepatic,  and  also  to  the  solar  plexus. 

The  Posterior  trunk  sends  branches  to  surround  the 
cardiac  orifice  of  the  stomach.  Many  branches  are  spread 
upon  the  under  side  of  the  great  curvature  of  the  stomach. 
Some  of  them  pass  in  the  course  of  the  coronary  artery 
to  the  coeliac,  and  unite  to  the  hepatic  and  splenic  plexuses; 
and  one  trunk,  which  is  thick  although  short,  proceeds 
to  the  solar  plexus. 

* See  Buisson,  in  the  continuation  of  the  Descriptive  Anatomy  of 
Bichat. 


332  Different  Functions  of  the  Laryngeal , 


The  Accessory  Nerve  of  Willis , 

YV  Inch  has  been  mentioned  as  associated  with  the  eighth 
pair  of  nerves,  within  the  cranium,  has  a very  peculiar 
origin. 

It  arises  by  small  filaments,  which  come  off  from  the 
spinal  marrow,  between  the  anterior  and  posterior  fasciculi 
of  the  cervical  nerves,  and  proceeds  upwards  to  the  great 
occipital  foramen,  between  these  fasciculi.  It  commences 
sometimes  at  the  sixth  or  seventh  cervical  vertebra,  and 
sometimes  about  the  fourth.  It  enters  the  cavity  of  the 
cranium  through  the  foramen  magnum,  and  proceeds  up- 
wards and  outwards,  so  as  to  join  the  eighth  pair  of  nerves 
at  some  distance  from  its  origin,  and  in  this  course  it  re- 
ceives filaments  from  the  medulla  oblongata. 

After  approaching  very  near  to  the  eighth  pair  of  nerves, 
it  accompanies  it  to  the  foramen  lacerum,  and  passes  out 
in  its  own  separate  sheath.  It  then  leaves  the  eighth  pair 
and  descends  towards  the  shoulder,  proceeding  through 
the  sterno-mastoid  muscle.  Soon  after  it  emerges  from  the 
cranium,  it  sends  a ramification  to  the  pharyngeal  branch 
of  the  Par  Vagum , and  another  to  the  Par  Vagum  itself. 
After  passing  through  the  upper  and  back  part  of  the 
sterno-mastoid  muscle,  it  terminates  in  the  trapezius.  It 
adheres  to  the  ninth  pair  of  nerves  as  it  passes  by  it,  and 
sends  a twig  to  the  sub-occipital  and  some  of  the  cervical 
nerves.  It  also  gives  ramifications  to  the  sterno-mastoid 
muscle  as  it  passes  through  it. 

It  has  already  been  stated  that  the  Laryngeal  and  Recur- 
rent Nerves  appear  to  answer  different  purposes  in  their 
distribution  to  the  Larynx. — When  both  of  the  recurrent 
nerves  are  divided  in  a living  animal,  the  voice  seems  to 
be  lost.  When  the  laryngeal  nerves  only  are  divided,  the 
strength  of  the  voice  remains,  but  it  is  flatter.  The  re- 
current nerves,  therefore,  seem  essential  to  the  formation 


333 


Ninth  Pair  of  Nerves. 

of  the  voice.  The  laryngeal  nerves  are  necessary  to  its 
modulation. 

The  history  of  the  investigation  of  this  subject  is  con- 
tained in  Mr.  Haighton’s  paper  in  the  third  volume 
of  Memoirs  of  the  Medical  Society  of  London. 


THE  NINTH  PAIR  OF  NERVES. 

Each  of  these  nerves  arises  from  the  groove  in  the 
medulla  oblongata,  between  the  corpora  pyramidalia  and 
the  corpora  olivaria.  Three  or  four  fasciculi,  of  distinct 
filaments,  unite  to  form  it.  Thus  composed,  it  proceeds 
to  the  anterior  condyloid  foramen  of  the  occipital  bone, 
and  passes  through  the  dura  mater.  It  seems  firmly  united, 
by  the  cellular  membrane,  to  the  eighth  pair,  and  to  the  first 
ganglion  of  the  sympathetic,  soon  after  it  passes  from  the 
occipital  bone.  It  is  either  connected  to  the  sub-occipital 
nerve  by  a small  ramification,  or  it  joins  a branch  which 
proceeds  from  the  sub-occipital  to  the  cervical,  and  bends 
round  the  transverse  process  of  the  atlas.  It  passes  be- 
tween the  internal  carotid  artery  and  the  internal  jugular 
vein,  and  crosses  the  external  carotid  at  the  origin  of  the 
occipital  artery.  At  this  place  it  generally  sends  down- 
wards a large  branch  which  is  called  the  Descendens  Noni . 
Passing  forwards,  it  is  on  the  outside  of  the  posterior 
portion  of  the  digastric  muscle,  and  inclines  downwards; 
but  near  the  tendon  of  the  muscle  it  turns  upwards,  and 
proceeds  on  the  inside  of  the  mylo-hyoideus,  where  it  di- 
vides into  ramifications,  which,  at  the  anterior  edge  of  the 
hyo-glossus  muscle,  begin  to  enter  in  the  substance  of 
the  tongue,  between  the  genio-glossus  and  the  lingualis 
muscles. 

Some  of  the  branches  of  this  nerve  unite  with  those  of 
the  lingual  branch  of  the  fifth  pair.  Others  are  distributed 
to  almost  all  the  muscles  connected  with  the  tongue. 

The  branch  called  Descendens  Noni  passes  down  in  the 


334  Sub-Occipital , or  Tenth  Pair  of  Nerves. 

course  of  the  common  carotid  artery,  and  sends  branches 
in  its  progress  to  the  upper  portions  of  the  coraco-hyoidei 
and  sterno- thyroidei  muscles;  it  unites  with  ramifications 
of  various  sizes  from  the  first,  second  and  third  cervical 
nerves,  which  form  a bow  under  the  sterno- mastoid  mus- 
cle, from  which  ramifications  go  to  the  lower  portions  of 
the  sterno  hyoidei  and  thyroidei  muscles  and  of  the 
coraco-hyoidei. 


OF  THE  CERVICAL  NERVES. 

The  tenth  or  last  pair  of  the  head,  commonly  called 
the  Sub -occipital,  may  be  arranged  with  these  nerves, 
because  they  arise,  like  them,  from  the  medulla  spinalis, 
and  are  distributed  to  the  nerves  on  the  neck. 

The  sub-occipital  Nerves 

Arise  on  each  side  of  the  spinal  marrow,  nearly  opposite 
to  the  interval  between  the  great  foramen  of  the  os  occi- 
pitis  and  the  atlas. 

Each  of  these  nerves  consists  of  an  anterior  and  pos- 
terior fasciculus,  or  bundle  of  fibres,  which  pass  out- 
wards immediately  under  the  vertebral  arteries,  and  form 
a ganglion,  from  which  proceeds  an  anterior  and  a pos- 
terior branch. 

The  anterior  branch  is  united  to  the  second  cervical 
nerve  below,  and  to  the  ninth  nerve,  or  the  hypoglossal, 
above.  It  also  sends  filaments  to  the  upper  ganglion  of 
the  great  sympathetic  nerve. 

The  posterior  branch  is  spent  upon  the  Recti,  the 
Obliqui , and  some  other  muscles  of  the  head. 

The  proper  Cervical  Nerves  consist  of  Seven  Pair;  of 
which  the  first  six  go  off  between  the  vertebras  of  the 
neck,  and  the  seventh  between  the  last  of  the  neck  and 
the  first  of  the  back. 


First  and  Second  Cervical  Nerves. 


335 


The  first  cervical  Nerve 
Passes  out  between  the  atlas  and  the  V ertebra  Dentata. 
It  originates  from  two  fasciculi,  which  are  connected  to 
each  other  at  a ganglion,  and  then  separate  into  an  ante- 
rior and  a posterior  branch.* 

The  anterior  branch  is  connected  by  filaments  with  the 
accessory  nerve,  with  the  ninth  pair  of  the  head,  and  with 
the  upper  ganglion  of  the  sympathetic.  It  is  also  connect- 
ed with  the  second  cervical  nerve;  and  sends  some 
branches  to  the  muscles  on  the  anterior  part  of  the  spine. 

The  posterior  branch,  after  communicating  with  the 
posterior  branches  of  the  sub- occipital  and  the  second 
nerves  of  the  neck,  perforates  the  complexus  muscle,  and 
ascending  upon  the  back  of  the  head,  is  distributed  with 
the  occipital  artery. 

THE  SECOND  CERVICAL  NERVE 

Sends  off,  from  its  Anterior  Branch , a twig  which  de- 
scends to  the  lower  cervical  ganglion  of  the  sympathetic, 
and  a considerable  ramification  to  the  third  cervical  nerve. 
It  also  sends  off  some  twigs  to  the  sterno- mastoid  muscle, 
and  others  to  join  the  accessory  nerve.  Some  of  its  small 
ramifications  pass  down  upon  the  external  jugular  vein, 
and  others  unite  with  the  descending  branch  of  the  ninth 
pair  of  the  head.  A small  branch  is  also  concerned  in  the 
formation  of  the  phrenic  nerve.  Two  larger  branches  of 
this  nerve  wind  found  the  posterior  edge  of  the  sterno- 
mastoid,  and  are  spread  under  the  integuments  of  the  an- 
terior, lateral  and  posterior  parts  of  the  neck  and  lower 
parts  of  the  head;  they  have  a communication  with  the 
portio  dura  of  the  seventh  pair.f — The  posterior  branch 

* This  arrangement  is  common  to  the  nerves  of  the  spine.  The 
ganglion  is  formed  by  the  posterior  fasciculus. 

t These  superficial  branches  have  sometimes  been  described  as 


336  Third  Cervical , and  Phrenic  Nerves. 

of  this  nerve  is  spent  upon  the  extensor  muscles  of  the 
head  and  neck. 

THE  THIRD  CERVICAL  NERVE 

Sends  down,  from  its  Anterior  Branch,  the  principal  trunk 
of  the  phrenic  nerve.  It  also  sends  twigs  to  the  fourth 
cervical,  to  the  lower  cervical  ganglion  of  the  intercostal, 
and  to  the  descending  branch  of  the  ninth  of  the  head. 
Some  of  its  branches  unite  with  twigs  of  the  accessory- 
nerve,  and  others  are  spent  upon  the  muscles  and  integu- 
ments of  the  shoulder  and  lower  part  of  the  neck.  A small 
Posterior  Branch  is  spent  upon  the  muscles  of  the  back 
of  the  neck. 

THE  NERVES  OF  THE  DIAPHRAGM 

Are  generally  denominated  the  Phrenic.  The  principal 
root  of  each  of  them  is  commonly  derived  from  the  third 
cervical  nerve,  but  frequently  the  second  and  the  fourth 
cervical  nerves  contribute  to  their  formation;  and  they 
are  sometimes  joined  by  a twig  which  is  derived  from 
the  ninth  pair. 

Each  nerve  proceeds  down  the  neck,  between  the  rectus 
capitis  major  and  the  scalenus  anticus,  and  continues  along 
the  fore  part  of  the  scalenus  anticus;  it  descends  into  the 
thorax  within  the  anterior  end  of  the  first  rib,  between 
the  subclavian  vein  and  the  artery.  It  sometimes  receives 
a twig  from  the  fifth  cervical  nerve,  and  a twig  passes  be- 
tween it  and  the  great  sympathetic.  After  entering  the 
thorax,  they  descend,  attached  to  the  mediastinum,  before 
the  root  of  the  lungs.  In  consequence  of  the  projection  of 
the  point  of  the  heart  to  the  left,  the  course  of  the  left  is 
a little  different  from  that  of  the  right;  that  of  the  right 

coming  from  a plexus;  but  they  often  arise  directly  from  the  Second 
Cervical  nerve. 


Remaining  Cervical  Nerves. — Brachial  Plexus.  337 

proceeding  in  a more  perpendicular  direction.  When  they 
arrive  at  the  diaphragm,  they  divide  into  many  ramifica- 
tions, which  have  a radiated  arrangement,  and  terminate 
on  the  fibres  of  that  muscle,  both  on  the  upper  and  lower 
surface.  Some  fibres  from  each  nerve  are  continued 
downward,  and  communicate  in  the  abdomen  with  fibres 
from  the  intercostal. 

THE  FOURTH,  FIFTH,  SIXTH,  AND  SEVENTH  CERVICAL 

NERVES, 

May  be  comprised  in  one  description.  They  pass  off  suc- 
cessively from  the  Medulla  Spinalis,  between  the  ver- 
tebras, like  the  other  nerves.  Their  Posterior  Branches 
are  generally  distributed  to  the  back  of  the  neck,  and  are 
very  small.  Their  Anterior  Branches  are  principally  ap- 
propriated to  the  upper  extremities,  and  are  large.  They 
generally  send  each  a small  twig  to  the  lower  cervical 
ganglion  of  the  intercostal  nerve,  and  a few  small  branches 
to  some  of  the  contiguous  muscles.  They  are  arranged 
and  combined  so  as  to  form  the  network,  now  to  be  de- 
scribed, which  is  called  the  Brachial  or  Axillary  Plexus ; 
and,  in  the  formation  of  this  plexus,  they  are  joined  by 
the  first  dorsal  nerve. 

The  BRACHIAL  PLEXUS 

Extends  from  the  lower  part  of  the  side  of  the  neck,  into 
the  arm-pit.  It  commences  in  the  following  manner.  The 
fourth  and  fifth  cervical  nerves  proceed  downwards,  and, 
after  uniting  to  each  other  about  an  inch  and  a half  below 
their  egress  from  the  spine,  they  separate  again,  almost 
immediately,  into  two  branches. 

The  sixth  cervical  nerve,  after  passing  downwards,  di- 
vides also  into  two  branches,  one  of  which  unites  with 
Vol.  II.  2 U 


338  Construction  of  the  Brachial  Plexus. 

the  uppermost  branch  that  proceeds  from  the  union  of  the 
fourth  and  fifth,  and  the  other  with  the  lowermost,  and 
they  all  proceed  downwards. 

The  seventh  cervical  is  joined  by  the  first  dorsal,  which 
proceeds  upwards,  and  unites  with  it  at  a short  distance 
from  the  spine.  The  cord  produced  by  their  junction  soon 
unites  with  one  of  the  cords  above  described.  As  these 
different  cords  proceed  downwards,  they  divide,  and  their 
branches  again  unite.  The  axillary  artery,  which  passes 
in  the  same  direction,  is  surrounded  by  them.  In  this 
manner  the  axillary  plexus  is  often  formed. 

The  muscles  about  the  shoulder,  both  before  and  be- 
hind, are  supplied  by  the  axillary  plexus.  Thus,  it  sends 
branches  to  the  Sub-scapularis,  Teres  Major,  and  Latissi- 
mus  Dorsi,  behind;  and  to  the  Pectoralis  Major  and  Minor , 
and  the  Mamma , before.  It  also  sends  off  a branch  called 
the  Scapularis , which  commonly  arises  from  the  upper 
part  of  the  plexus,  and  proceeds  through  the  notch  in  the 
upper  costa  of  the  scapula,  to  the  supra  and  infra  spinatus, 
teres  minor,  &c. 

Nerves  of  the  Arm. 

All  the  great  nerves  of  the  arm  are  derived  from  the 
axillary  plexus.  There  are  six  of  them,  which  are  denomi- 
nated The  Musculo  Cutaneus ; The  Median ;*  The  Cubital, 
or  Ulnar;  The  Internal  Cutaneus;  The  Radial  or  Muscu- 
lar Spiral;  and  the  Circumflex  or  Articidar. 

The  MUSCULO  CUTANEUS,  or  PERFORATING  NERVE, 

passes  obliquely  through  the  upper  part  of  the  coraco 
brachialis  muscle.  Before  it  enters  the  muscle,  it  sends 
a branch  to  it.  After  leaving  the  muscle,  it  passes  down 
the  arm  between  the  biceps  and  the  brachialis  internus,  to 
which  it  also  gives  branches.  It  proceeds  to  the  outside 


* Sometimes  called  Radial- 


Musculo  Cutaneus  and  Median  Nerves.  339 

of  the  biceps,  and  continues  under  the  median  cephalic 
vein  to  the  anterior  and  external  part  of  the  fore  arm; 
along  which  it  passes,  under  the  integuments.  On  the 
lower  part  of  the  fore  arm  it  divides  into  many  branches, 
which  extend  to  the  root  of  the  thumb  and  the  back  of 
the  hand,  and  terminate  in  the  integuments. 

The  median  nerve,  which  is  one  of  the  largest  of 
the  arm,  often  proceeds  from  the  axillary  plexus  next  to 
the  musculo  cutaneus;  it  passes  down  the  arm,  very  hear 
the  humeral  artery,  within  the  edge  of  the  biceps  flexor 
muscle,  and,  during  this  Course,  gives  off  no  branches  of 
any  importance.  After  passing  the  bend  of  the  elbow,  it 
proceeds,  under  the  aponeurosis  of  the  biceps,  between 
the  brachialis  interims  and  the  pronator  teres,  and  con- 
tinues down  near  the  middle  cf  the  fore  arm,  between  the 
flexor  sublimis  and  the  flexor  profundus.  At  the  elbow  it 
sends  branches  to  several  muscles  on  the  anterior  side  of 
the  fore  arm,  and  to  the  integuments.  Among  these 
branches  is  one,  called  the  Interosseal  Nerve , which 
passes  down  on  the  anterior  surface  of  the  interosseal 
ligament,  with  the  artery  of  that  name.  This  nerve  sends 
branches,  in  its  course,  to  the  long  flexor  of  the  thumb 
and  the  deep  flexor  of  the  fingers.  When  it  arrives  at  the 
pronator  quadratus,  it  sends  branches  to  that  muscle,  and, 
passing  between  it  and  the  interosseous  ligament,  per- 
forates the  ligament,  and  soon  terminates  on  the  posterior 
side  of  the  wrist  and  hand. 

As  the  median  Nerve  proceeds  downwards,  it  bJe= 
comes  more  superficial;  and  continuing  among  the  ten- 
dons  of  the  flexors  of  the  fingers,  it  gives  oft'  a branch 
which  is  principally  spent  upon  the  integuments  of  the 
palm  of  the  hand.  This  great  nerve  passes  with  the  ten- 
dons under  the  annular  ligament;  and  immediately  after, 
while  it  is  covered  by  the  Aponeurosis  Palmar  is,  and  by 
that  portion  of  the  artery  which  is  called  Arcus  Sublimis 
it  divides  into  branches,  which  separate  from  each  other 


340 


Cubital  dr  Ulnar  Nerve. 


at  acute  angles,  and  subdivide  so  as  to  send  a ramification 
to  each  side  of  the  thumb,  of  the  index,  and  of  the  middle 
finger;  and  to  the  radial  side  of  the  ring  finger. 

The  cubital  or  ulnar  nerve  is  also  of  conside- 
rable size.  It  passes  down  on  the  inside  of  the  triceps  ex- 
tensor muscle,  to  the  great  groove  formed  by  the  olecra- 
non process  and  the  internal  condyle  of  the  os  humeri; 
and  in  this  course  it  often  sends  a branch  to  the  triceps, 
and  some  smaller  twigs  to  the  upper  part  of  the  fore  arm. 
From  the  groove  it  proceeds  on  the  anterior  part  of  the 
fore  arm,  between  the  flexor  carpi  ulnaris  and  the  flexor 
sublimis,  to  the  wrist.  At  a small  distance  above  the  wrist 
it  sends  off  a branch,  called  the  Dorsalis , which  passes  be- 
tween the  flexor  ulnaris  and  the  ulna,  to  the  back  of  the  fore 
arm  and  wrist,  where,  after  sending  ramifications  to  the 
integuments  and  contiguous  parts,  it  divides  into  branch- 
es which  pass  to  the  little  finger  and  the  finger  next  to  it. 
Those  branches  send  off,  in  their  course,  many  twigs 
which  pass  to  the  skin  and  cellular  substance. 

The  ulnar  nerve  then  proceeds  with  the  artery,  over 
the  annular  ligament,  on  the  radial  side  of  the  os  pisiforme, 
and  divides  into  two  branches;  one  of  which  is  superficial, 
and  the  other  deep-seated. 

The  Superficial  divides  into  two  principal  branches,  an 
external  and  an  internal.  The  external  passes  under  the 
aponeurosis  palmaris;  and,  after  sending  a branch  to  com- 
bine with  one  from  the  median,  and  some  twigs  to  the 
contiguous  muscles,  it  subdivides  into  two  branches,  one 
of  which  goes  to  the  ulnar  side  of  the  ring  finger  and  the 
opposite  side  of  the  little  finger.  The  other  branch  sends 
off  some  twigs  to  the  muscles,  and  proceeds  along  the 
ulnar  side  of  the  little  finger. 

The  Deep-seated  palmar  branch  of  the  ulnar  nerve, 
passes  between  the  muscles  of  the  little  finger,  under  the 
tendons  of  the  flexors,  and  accompanies  the  deep-seated 
arterial  arch  in  the  palm  of  the  hand,  giving  branches  to 
the  interossei,  and  other  contiguous  muscles.  • 


341 


Radial,  or  Muscular  Spiral  Nerve. 

The  radial  or  muscular  spiral  nerve  is  one  of 
the  largest  nerves  of  the  arm.  It  passes  from  the  axillary 
plexus  downward,  backward  and  outward,  under  the  tri- 
ceps muscle,  to  the  external  side  of  the  o's  humeri.  In 
this  course  it  gives  off  several  branches  to  the  different 
portions  of  the  triceps.  It  also  frequently  gives  off  a large 
branch,  which  passes  downwards  on  the  outside  of  the 
olecranon,  to  the  back  of  the  fore  arm,  and  continues  to 
the  back  of  the  hand,  furnishing  many  branches  which 
terminate  in  the  integuments.  It  then  proceeds  downwards 
between  the  supinator  radii  longus  and  the  brachialis  in- 
ternus.  Immediately  after  passing  the  articulation  of  the 
elbow,  it  divides  into  two  branches  denominated  the  Su- 
perficial zx\<S.  the  Profound.  The  Superficial  soon  joins  the 
radial  artery,  and  proceeds  downwards,  sending  branches 
to  the  contiguous  muscles.  In  its  course  about  the  middle 
of  the  arm,  it  crosses  the  tendon  of  the  supinator  longus, 
and  proceeds  between  it  and  the  tendon  of  the  extensor 
carpi  radialis  longior;  it  soon  after  divides  into  two 
branches,  which  are  principally  distributed  to  the  thumb 
and  forefinger,  and  also  to  the  integuments. 

The  Profound  branch  proceeds  to  the  back  of  the  fore 
arm  under  the  radial  extensor,  and  continues  to  the  back 
of  the  wrist  and  hand.  Into  this  course  it  divides  into  two 
branches,  which  are  distributed  to  the  contiguous  muscles 
and  tendons,  and  the  integuments. 

The  internal  cutaneus  nerve  is  the  smallest  of  the 
nerves  which  proceed  from  the  axillary  plexus.  It  de- 
scends in  the  course  of  the  basiiic  vein,  and  very  near  it. 
Above  the  elbow  it  divides  into  an  Internal  Branch , 
which  proceeds  over  the  Basilic  Vein,  and  separates  into 
branches  that  pass  down  on  the  side  of  the  fore  arm; 
and  an  External  Branch  that  passes  under  the  Median 
Basilic  Tew,  and  continues  down  on- the  anterior  part 
of  the  fore  arm. 

The  ARTI  cular  or  circumflex  nerve  proceeds 


342 


The  Dorsal  Nerves. 


backwards  from  the  plexus,  between  the  teres  major  and 
minor,  and  passes  nearly  round  the  body  of  the  os  humeri, 
at  a small  distance  below  its  head.  It  is  distributed  to  the 
contiguous  muscles  and  to  the  articulation;  but  its  princi- 
pal branches  terminate  in  the  deltoid  muscle. 

THE  DORSAL  NERVES 

Proceed  from  the  cavity  of  the  spine  between  the  dorsal 
vertebrae.  They  are  sometimes  called  Intercostals , be- 
cause  they  pass  between  the  ribs,  like  the  bloodvessels  of 
that  name.  There  are  twelve  pair  of  them,  and  they  are 
named  numerically,  beginning  from  above. 

These  nerves  proceed  from  the  medulla  spinalis  by  two 
fasciculi  of  fibres — one  from  each  of  its  lateral  portions, 
— the  posterior  fasciculus  is  the  largest.  After  passing 
through  the  lateral  foramen  and  the  dura  mater,  a ganglion 
is  formed  by  the  posterior  fasciculus:  the  anterior  fascicu- 
lus unites  to  this  ganglion  at  its  external  extremity;  and 
one  nerve  is  formed,  which  almost  immediately  divides 
into  an  anterior  and  a posterior  branch,  of  which  the  an- 
terior is  the  largest. 

The  posterior  branch  proceeds  backwards,  and  is  dis- 
tributed to  the  muscles  of  the  back.  The  anterior  branch 
passes  towards  the  angle  of  the  rib,  in  contact  with  the 
pleura.  Soon  after  its  origin,  this  anterior  branch  sends 
off  two  ramifications  which  unite  to  the  intercostal  nerve, 
at  the  ganglion;  it  then  proceeds  forwards  with  the  blood" 
vessels,  between  the  internal  and  external  intercostal  mus- 
cles, in  the  groove  near  the  lower  margin  of  the  ribs; 
and  terminates  on  the  anterior  part  of  the  thorax.  In  its 
course  it  sends  branches,  not  only  to  the  intercostal  mus- 
cles and  pleura,  but  to  the  other  muscles  and  the  integu- 
ments of  the  thorax. 

Some  of  the  dorsal  nerves  differ  from  the  others,  as  to 
the  ramifications  which  they  send  off. 


General  Account  of  the  Lumbar  Nerves.  343 

The  First  Nerve , of  this  order,  joins  the  lower  cervical 
nerves  in  the  axillary  plexus;  but  it  sends  off  the  ramifi- 
cations to  the  sympathetic;  and  also  a branch,  which  passes 
under  the  first  rib,  like  the  other  dorsal  nerves. 

The  Second  Nerve , sends  off  a branch,  which  passes 
through  the  external  intercostal  muscle  into  the  axilla, 
and  combines  there  with  a branch  of  the  cutaneous  nerve, 
being  distributed  to  the  internal  and  posterior  part  of  the 
arm. 

The  third  dorsal  nerve  also  sends  off  a branch,  which 
is  distributed  to  the  axilla  and  the  back  part  of  the  arm. 

These  branches  of  the  second  and  third  dorsal  nerves, 
are  called  intercosto-humeral  nerves. 

The  lower  dorsal  nerves  supply  the  muscles  and  integu- 
ments  of  the  abdomen. 


Of  the  LUMBAR  Nerves. 

There  are  five  pair  of  these  nerves.  The  first  of  them 
passes  off  between  the  first  and  second  of  the  lumbar  ver- 
tebras, and  the  others  succeed  regularly;  so  that  the  last 
pair  is  situated  between  the  last  lumbar  vertebra  and  the 
sacrum. 

The  first  lumbar  nerves  arise  from  the  medulla  spinalis, 
before  it  forms  the  cauda  equina;  the  other  four  pair  are 
formed  by  the  cauda  equina. 

They  commence  by  anterior  and  posterior  fasciculi, 
which  are  united  at  a ganglion.  From  this  ganglion, 
anterior  and  posterior  branches  go  off,  which  are  very 
different  in  size,  the  anterior  being  the  largest. 

The  posterior  branches  are  distributed  to  the  muscles 
Of  the  back.  The  anterior  send  branches  to  the  ganglions 
of  the  sympathetic  nerve,  and  also  communicate  with 
each  other  to  form  the  Lumbar  Plexus,  which  is  situated 
on  the  lateral  parts  of  the  bodies  of  the  Lumbar  Vertebrae, 


344  Lumbar  Nerves. — Lumbar  Plexus . 

before  their  transverse  processes,  and  supplies  nerves  to 
the  muscles  of  the  thigh. 

THE  FIRST  LUMBAR  NERVE 

Is  connected,  by  its  anterior  branch,  to  the  last  dorsal  and 
the  second  lumbar.  From  the  same  branch,  ramifications 
go  off  to  the  Quadratus  Lumborum,  and  obliquely  across 
that  muscle,  to  the  lower  part  of  the  abdominal  muscles 
near  the  spine  of  the  ileum. 

THE  SECOND  LUMBAR  NERVE 

Sends  off  a muscular  branch  downwards  and  outwards:  it 
also  sends  off  the  small  branch,  called  the  External  Sper- 
matic, which  passes  down  in  such  a direction,  that  it  per- 
forates the  transversalis  and  the  obliquus  internus  muscles, 
near  their  lower  margin,  at  a small  distance  from  the 
superior  anterior  spine  of  the  ileum,  and  then  proceeds 
within  the  lower  edge  of  the  tendon  of  the  external 
oblique  to  tire  abdominal  ring,  through  which  it  passes. 
In  the  male  it  is  distributed  to  the  spermatic  cord  and 
scrotum,  and  in  the  female,  to  the  labia  pudendi.  In  the 
female  it  also  sends  a branch  to  the  uterus.*  The  Second 
Lumbar , after  sending  off  these  branches,  passes  down- 
wards, and  joins  the  Third  lumbar  nerve.  From  this 
union  of  the  second  and  third  nerves,  a branch  called  the 
Cutaneus  Medius , which  will  be  soon  described,  proceeds 
downwards. 

After  sending  off  this  branch,  the  united  trunk  of  the 
second  and  third  joins  the  Fourth;  and  from  this  union 
are  sent  off  the  Obturator  Nerve , which  passes  through 
the  aperture  in  the  membrane  that  closes  the  foramen 
thyroideum;  the  Crural  Nerve,  which  passes  under  Pou- 

* The  external  spermatic  often  comes  off  from  the  first  lumbar 
nerve. 


Obturator  Nerve.— Crural  Nerve. 


345 


part’s  ligament;  and  a third  branch  that  proceeds  down- 
wards, and  joins  the  Fifth  lumbar  nerve.  The  Fifth  lum- 
bar nerve,  with  this  accession  from  above,  descends  into 
the  pelvis,  and  unites  with  the  sacral  nerves. 

This  arrangement  of  the  lumbar  nerves  constitutes  the 
Lumbar  Plexus , which,  has  been  already  stated,  fur- 
nishes three  nerves  to  the  lower  extremity,  viz.  the  Cu- 
taneus  Medius,  the  Obturator , and  the  Crural  Nerve. 

The  Cutaneus  Medius  which  arises  from  the  union  of 
the  second  and  third  nerves,  as  has  been  already  observed, 
proceeds  downwards,  and  frequently  adheres  to  the  crural 
nerve,  for  a short  distance,  near  Poupart’s  ligament,  but 
soon  leaves  it,  and  descends  on  the  inside  of  the  thigh, 
supplying  the  integuments  as  low  as  the  knee, 

THE  OBTURATOR  NERVE 

Descends  into  the  pelvis,  and  passes  out  of  it  at  the  upper 
part  of  the  foramen  thvroideum;  proceeding  downwards 
in  an  internal  direction,  to  be  distributed  on  the  inside  of 
the  thigh. 

This  nerve  is  generally  accompanied  by  the  obturator 
artery  and  vein;  the  artery  being  above,  and  the  vein 
below  it.  When  it  has  arrived  at  the  foramen  ovale  or 
thyroideum,  it  sends  off  a branch  to  the  internal  and  ex- 
ternal obturator  muscles,  and,  after  passing  these  muscles, 
divides  into  two  branches  which  are  distributed  to  the 
muscles  on  the  inside  of  the  thighs,  the  adductors,  the 
pectineus,  the  gracilis,  &c. 

THE  CRURAL  NERVE 

Is  situated  at  first  behind,  and  then  on  the  outside  of  the 
psoas  muscle.  It  passes  under  Poupart’s  ligament  with 
the  great  femoral  vessels,  being  on  the  outside  of  the 
artery. 

VOL.  II. 


2 X 


Crural  Nerve. — Sacral  Nerve s. 


3 46 

It  is  distributed  to  the  integuments,  and  also  to  the 
muscles,  which  are  situated  on  the  anterior  and  internal 
parts  of  the  thigh.  Some  of  its  ramifications  go  off  before 
it  passes  under  Poupart’s  ligament.  Several  of  them  are 
spent  upon  the  integuments,  and  are  therefore  denomina- 
ted Cutaneous. — They  are  distinguished  by  the  terms 
Cutaneus  Anterior , Cutaneus  Internus,  &c.,  according  to 
their  situations. 

The  deep-seated  branches  are  the  largest.  They  are 
principally  spent  upon  the  muscles  on  the  anterior  and 
the  internal  side  of  the  thigh,  viz.  the  four  extensors,  the 
adductors,  the  pectineus,  the  sartorius,  and  the  gracilis. 
Among  these  nerves  there  is  one,  called  the  Saphenus , 
which  has  a different  destination.  It  accompanies  the  great 
artery  of  the  thigh  to  the  place  where  it  perforates  the 
Adductors:  it  there  separates  from  the  artery,  and  passes 
over  the  tendon  of  the  Adductors , under  the  sartorius 
muscle;  thence  it  continues,  with  the  great  saphena  vein, 
on  the  inside  of  the  leg,  to  the  internal  ankle;  sending 
branches  to  the  integuments  in  its  course.  It  terminates  in 
skin  and  cellular  substance  on  the  upper  and  internal  sur- 
face of  the  foot. 

The  SACRAL  Nerves 

Are  composed  of  those  cords  of  the  cauda  equina,  which 
remain  after  the  formation  of  the  lumbar  nerves.  They  are 
frequently  stated  to  consist  of  five  or  six  pair,  four  of 
which  pass  through  the  foramina  of  the  sacrum,  and  the 
fifth  between  the  sacrum  and  the  oscoccygis.*  The  cords 
of  which  they  are  respectively  composed  arise  by  anterior 
and  posterior  fasciculi.  When  they  have  arrived  opposite 
to  the  foramina  of  the  sacrum,  through  which  they  are  to 
pass,  a ganglion  is  formed,  at  which  they  unite,  and  then 

# The  sixth  pair,  when  they  exist,  proceed  in  a groove  in  the  os 
coccygis. 


Sciatic  Plexus. — Pudic  Nei~ve. 


347 


divide  into  anterior  and  posterior  branches.*  The  upper- 
most of  the  anterior  branches  are  large,  and  pass  through 
the  anterior  foramina  of  the  sacrum.  The  posterior  are 
small,  and  go  through  the  posterior  foramina. 

The  Posterior  Branches  are  generally  spent  upon  the 
muscles  which  lie  on  the  sacrum,  and  posterior  parts  of 
the  pelvis,  externally. 

The  anterior  branches  of  the  three  first  nerves  send  ra- 
mifications to  the  sympathetic.  They  unite  to  each  other, 
and  are  joined  by  the  last  lumbar  nerve,  and  by  a branch 
of  the  fourth  sacral,  in  the  formation  of  the  great  sciatic 
nerve.  This  union  constitutes  the  sciatic  plexus. 

The  anterior  branch  of  the  fourth  nerve  transmits 
branches  to  the  sympathetic:  it  also  sometimes  sends  a 
branch  to  the  united  nerves  above,  or  the  sciatic  plexus. 
It  sends  branches  to  the  hypogastric  plexus,  and  to  the 
contiguous  muscles. 

The  fifth  and  sixth  pairs,  which  are  very  small,  termi- 
nate also  in  the  contiguous  muscles  and  in  the  integu- 
ments. 

From  the  sciatic  plexus,  or  the  nerves  which  com- 
pose it,  several  smaller  branches  go  off.  There  are  gene- 
rally two  which  pass  off  backwards  through  the  ischiatic 
notch,  and  are  denominated . Gluteal , as  they  are  distri- 
buted to  the  glutei  muscles.  From  the  lowermost  of  these 
a branch  descends  on  the  thigh. 

The  Pudic  Nerve,  which  is  appropriated  to  the  organs 
of  generation,  also  passes  off  from  this  plexus,  and  ap- 
pears to  consist  of  fibres  which  are  derived  from  each  of 
the  nerves  that  compose  it.  It  proceeds  between  the  sacro- 
sciatic  ligaments,  and  divides  into  two  branches — an  in- 
ferior and  a superior.  The  inferior  passes  between  the 
erector  penis  and  the  accelerator  urinae  muscles,  and  is 

* The  ganglions  of  the  fourth  and  fifth  nerves  are  extremely  small 
ajid  not  so  near  the  foramina  as  those  of  the  others. 


348  Course  of  the  Great  Sciatic  Nerve. 

distributed  to  those  muscles,  to  the  bulb  of  the  urethra 
and  the  interior  of  that  canal,  to  the  scrotum  and  dartos. 

The  superior  proceeds  along  the  os  pubis  to  the  sym- 
physis, and  passes  between  the  bone  and  the  body  of  the 
penis  to  the  dorsum.  A considerable  branch  accompanies 
the  artery  on  the  dorsum,  and  terminates,  by  many  rami- 
fications, on  the  glans  penis;  after  sending  branches  in  its 
course  to  :he  integuments  generally,  and  to  the  prepuce. 

In  females,  the  Inferior  Pudic  Nerve  proceeds  along 
the  external  labia  pudendi  to  the  mons  veneris,  sending 
off  many  ramifications  in  its  course. 

The  Superior  Pudic  Nerve  proceeds,  as  in  males,  along 
the  branch  of  the  pubis  to  the  superior  surface  of  the 
clitoris,  and  terminates  principally  upon  the  extremity  of 
that  organ. 

The  sacral  nerves  unite  in  the  sciatic  plexus  to  form 
the  great  nerve  of  the  lower  extremity,  which  is  next  to 
be  described. 

The  GREAT  SCIATIC  Nerve 

Proceeds  from  the  pelvis  through  the  ischiatic  notch,  be- 
tween the  pyramidalis  and  the  superior  gemellus  muscle: 
it  then  passes  down  to  the  back  part  of  the  thigh,  between 
the  tuberosity  of  the  ischium  and  the  great  trochanter  of 
the  os  femoris;  and  continues  downwards,  inclining  from 
within  outwards,  to  the  ham,  where  it  is  situated  between 
the  tendons  of  the  semi-tendiuosus  and  semi-membranosus 
on  the  internal  side,  and  the  tendon  of  the  biceps  on  the 
external.  In  this  course  it  sends  off  branches  to  the  mus- 
cles  on  the  posterior  part  of  the  thigh. 

As  the  great  nerve  passes  down  the  thigh,  it  sends  off 
obliquely,  downwards  and  outwards,  a large  branch  which 
is  called  the  Fibular,  that  passes  across  the  head  of  the 
fibula  to  the  external  and  anterior  part  of  the  leg.  The 
place  where  this  branch  separates  from  the  main  nerve 


Distribution  of  the  Fibular  Nerve.  349 

is  different  in  different  subjects.  It  continues  in  contact 
with  it  for  some  distance,  connected  only  by  cellular 
membrane. 

THE  FIBULAR  OR  PERONEAL  NERVE 

Proceeds  downwards  on  the  inside  of  the  tendon  of  the 
biceps,  and  crosses  obliquely  to  the  outside  of  the  external 
head  of  the  gastroc  nemius:  it  then  passes  inwards  between 
the  long  peroneus  muscle  and  the  fibula;  and  descend- 
ing between  the  muscles  on  the  front  of  the  leg,  divides 
into  two  branches,  one  of  which  inclines  to  the  exterior* 
side  of  the  leg,  and  the  other  preserves  an  internal  situa- 
tion. In  its  course  from  the  great  sciatic  nerve  to  the 
fibula,  it  sends  off  some  superficial  ramifications.  The  two 
branches  into  which  it  divides,  after  passing  over  the 
fibula,  continue  downwards.  The  Internal , after  supplying 
the  muscles  on  the  anterior  part  of  the  leg,  passes  under 
the  annular  ligament  like  the  anterior  tibial  artery;  and  on 
the  upper  part  of  the  foot,  divides  into  two  ramifications, 
one  of  which  proceeds  forwards  near  the  internal  edge  of 
the  foot,  and  the  other  near  the  external;  they  divide 
again,  and  are  distributed  to  the  parts  on  the  upper  surface 
of  the  foot,  one  of  their  ramuli  descending  with  the  con- 
tinuation of  the  anterior  tibial  artery  to  the  sole  of  the 
foot. 

The  External  Branch  of  the  fibular  nerve,  as  it  pro- 
ceeds dowmvards,  supplies  ramifications  to  the  contiguous 
muscles,  and,  passing  through  the  fascia  on  the  outside  of 
the  leg,  continues  between  it  and  the  skin  towards  the 
foot.  In  this  course  it  generally  divides  into  two  branches 
which  are  spent  upon  the  upper  surface  of  the  foot. 

The  GREAT  SCIATIC  Nerve , after  the  fibular 
nerve  leaves  it,  continues  down  the  thigh,  between  the 
tendons  of  the  flexors,  behind  the  great  bloodvessels,  and 
of  course  exterior  to  them. 


350  Distribution  of  the  Tibial  Nerve. 

In  the  ham,  this  great  nerve  takes  the  name  of  POPLI- 
TEAL, and  proceeds  across  the  articulation  of  the  knee, 
between  the  heads  of  the  gastroc  nemii,  to  the  posterior 
side  of  the  tibia:  here  it  passes  through  the  upper  portion 
of  the  soleus  or  gastroc  nemius  internus,  and  continues 
between  it  and  the  long  flexor  of  the  toes,  near  the  Pos- 
rior  Tibial  Artery;  descending  with  that  artery  to  the 
hollow  of  the  os  calcis.  In  this  situation  it  has  the  name  of 

POSTERIOR  TIBIAL  NERVE. 

/ 

At  the  commencement  of  this  course,  a small  distance 
below  the  internal  condyle  of  the  os  femoris,  it  sends  off  a 
branch  of  considerable  size  called  the  Communicans  Tibia, 
or  Saphena  Externa , which  passes  down  behind  the 
gastroc  nemii,  and  gradually  inclines  externally,  so  that 
it  is  situated  on  the  external  edge  of  the  tendo  Achillis, 
soon  after  the  commencement  of  that  tendon,  and  pro- 
ceeds behind  the  external  ankle,  near  the  outer  side  of  the 
foot,  to  the  smaller  toes;  distributing  branches  to  the  con- 
tiguous parts.  In  its  course  on  the  back  of  the  leg,  it  sends 
off  a branch  which  unites  with  one  of  the  superficial  rami- 
fications of  the  fibular  nerve,  and  descends  to  the  outer 
part  of  the  foot. 

The  tibial  Nerve , in  its  course  downwards,  sends 
branches  to  the  contiguous  muscles;  and  a few  twigs  which 
form  a species  of  network  on  the  artery.  In  the  hollow  of 
the  os  calcis  it  sends  off  a superficial  branch  to  the  integu- 
ments of  the  sole  of  the  foot,  which  proceeds  on  the  out- 
side of  the  aponeurosis  plantaris:  it  there  also  divides  into 
branches,  which  are  denominated  the  Internal  and  Exter- 
nal Plantar  Nerves. 

The  Internal  Plantar  Nerve  proceeds  forwards,  along 
side  of  the  tendon  of  the  long  flexor  muscle  of  the  great 
toe,  giving  off  small  branches  in  its  course.  About  the 
middle  of  the  foot  it  divides  into  four  branches,  one  of 


Commencement  of  the  Sympathetic  Nerve.  351 

which  proceeds  to  the  inside  of  the  great  toe;  and  a second 
to  the  angle  formed  by  the  great  toe  and  the  toe  next  to  it, 
where  it  divides  and  sends  a branch  to  the  opposite  sides 
of  those  toes:  the  other  two  branches  are  distributed  in  a 
similar  manner,  to  the  succeeding  toes.  These  digital 
brandies  are  connected  with  each  other  by  small  ramifica- 
tions. 

The  External  Plantar  Nerve  proceeds  with  the  external 
plantar  artery  towards  the  external  side  of  the  foot,  be- 
tween the  short  flexor  of  the  toes  and  the  flexor  accessorius. 
Near  the  external  edge  of  the  foot,  about  the  posterior 
end  of  the  metacarpal  bones,  it  divides  into  three  branches. 
One  proceeds  to  the  outside  of  the  little  toe;  another  passes 
to  the  angle  between  the  fourth  toe  and  the  little  toe,  and 
divides  into  branches  which  are  distributed  to  the  cor- 
responding sides  of  these  toes.  The  third  branch  proceeds 
more  deeply  in  the  foot,  from  the  external  towards  the 
internal  edge  of  it,  and  is  spent  upon  the  deep-seated 
contiguous  muscles. 

THE  GREAT  SYMPATHETIC  OR  INTERCOSTAL  NERVE 

Commences  in  the  cranium  with  those  small  ramifications 
of  the  pterygoid  branch  of  the  upper  maxillary  nerve,  and 
of  the  sixth  pair,  which  accompany  the  carotid  artery 
through  the  canal  in  the  petrous  portion  of  the  temporal 
bone.  These  small  nerves  form  a network  which  sur- 
rounds the  artery  in  the  canal,  and  gives  rise  to  the 
incipient  sympathetic,  a small  cord  which  passes  down 
close  to  the  nerves  of  the  eighth  and  ninth  pair  of  the 
neck.  Opposite  to  the  second  cervical  vertebra,  this  nerve 
is  swelled  or  dilated,  so  as  to  form  a body  of  a light  red 
colour,  which  is  more  than  an  inch  in  length,  and  has  the 
form  of  two  cones  united  to  each  other  at  their  bases. 
This  is  the  Superior  Cervical  Ganglion  of  the  Sympathetic 
Nerve,  and  from  it  the  nerve  descends,  behind  the  Par 


352  First  Ganglion , and  other  Cervical 

Fagum,  on  the  front  part  of  the  neck.  This  ganglion  re- 
ceives twigs  from  the  first,  second,  third  and  fourth  pairs 
of  cervical  nerves,  and  also  from  the  eighth  and  ninth 
nerves  of  the  head.  It  sends  off  several  twigs,  which  pass 
behind  the  carotid  artery,  at  its  bifurcation,  and  are  joined, 
by  twigs  of  the  Portio  Dura  and  the  Glosso- Pharyngeal 
nerves.  From  these  united  twigs  proceed  very  small  ra- 
mifications, which  accompany  several  branches  of  the  ex- 
ternal carotid  artery,  and  some  of  them  pass  down  with 
the  Common  Carotid. 

This  superior  ganglion  also  furnishes  small  twigs  which 
accompany  the  Glosso- Pharyngeal  to  the  tongue  and  pha- 
rynx. Sometimes  a twig  from  it  passes  on  the  back  part 
of  the  thyroid  gland  to  communicate  with  the  recurrent 
nerve.  From  this  ganglion  go  off  some  small  branches, 
which,  uniting  with  others  from  the  superior  laryngeal 
nerves,  form  the  superior  or  superficial  cardiac  nerve, 
which  will  be  soon  described. 

The  trunk  of  the  Sympathetic  Nerve  descends,  on  the 
front  of  the  neck,  from  this  ganglion,  as  has  been  already 
stated.  In  its  course  it  receives  very  small  twigs  from 
the  fourth  and  fifth  cervical  nerves,  and  sends  some  very 
small  twigs  which  appear  to  go  to  the  oesophagus,  and 
some  which  unite  to  the  laryngeal  nerve  and  go  to  the 
thyroid  gland.  Some  twigs,  which  are  larger,  proceed 
from  it  into  the  thorax,  and  go  to  the  cardiac  plexus  here- 
after to  be  described. 

Opposite  to  the  interval  between  the  fifth  and  sixth 
cervical  vertebras  it  forms  another  ganglion,  of  an  irregu- 
lar shape,  much  smaller  than  the  first.  This  ganglion,  in 
different  subjects,  differs  in  size  as  well  as  in  several 
other  respects.  Sometimes  it  is  entirely  wanting,  and 
sometimes  it  is  doubled.  It  is  denominated  the  Middle 
Cervical,  or  Thyroid  Ganglion. — When  the  fourth,  fifth, 
and  sixth  cervical  nerves  do  not  send  ramifications  to  the 


Ganglions  and  Branches  of  the  Sympathetic.  353 

sympathetic  nerve  above,  this  ganglion  receives  twigs 
from  them. 

The  Middle  Cervical , or  Thyroid  Ganglion , sends  many 
ramifications  downwards.  Some  of  them  enter  the  thorax 
and  contribute  to  the  formation  of  the  Cardiac  Plexus; 
others  accompany  the  inferior  thyroid  artery,  and,  with 
twigs  from  the  recurrent  nerve,  form  a plexus  which  ex- 
tends towards  the  thyroid  gland.  Some  proceed  down- 
wards before,  and  others  behind,  the  subclavian  artery, 
to  the  next  ganglion;  and  among  them  is  generally  one 
which  may  be  regarded  as  the  trunk  of  the  Sympathetic. 

This  third  Ganglion  is  denominated  the  Inferior  Cervi- 
cal, or  the  First  Thoracic.  It  is  almost  constantly  found 
in  the  same  situation,  viz.  between  the  transverse  process 
of  the  last  cervical  vertebra  and  the  head  of  the  first  rib, 
and  is  partly  covered  by  the  origin  of  the  vertebral  artery. 
It  is  generally  larger  than  the  middle  ganglion.  It  receives 
branches  from  the  sixth  and  seventh  cervical,  and  the  two 
first  dorsal  nerves.  Ramifications  pass  from  it  to  the  par 
vagum  and  recurrent  nerve,  and  also  to  the  cardiac  and 
pulmonary  plexus. 

From  this  ganglion  the  Sympathetic  Nerve  proceeds 
downwards  on  the  side  of  the  spine,  as  will  be  described 
hereafter. 

The  Nerves  of  the  Heart , 

Being  derived  from  branches  which  have  already  been 
mentioned,  are  now  to  be  described. 

They  arise  principally  from  an  arrangement  of  nerves 
denominated  the  Cardiac  Plexus , or  Plexuses,  which  is 
situated  about  the  curve  of  the  aorta,  and  extends,  on  the 
posterior  side  of  it,  from  the  root  of  the  arteria  innomi- 
nata  to  the  bifurcation  of  the  pulmonary  artery.  This 
plexus  is  composed  of  nerves  which  are  principally  form- 
ed by  the  union  of  small  ramifications  that  are  derived 
Vol.  II.  2 Y 


354  Branches  of  the  Sympathetic. 

from  the  three  above  mentioned  ganglions  of  the  Sympa- 
thetic Nerve , and  the  nerve  itself;  and  also  from  the  Par 
Vagum  and  some  of  its  branches. 

These  nerves  are  denominated  the  Cardiac.  They  de- 
scend on  their  respective  sides  of  the  neck,  but  are  some- 
what different  on  the  different  sides.  On  the  right  side  three 
nerves  have  been  described  as  particularly  entitled  to  this 
name,  and  on  the  lejt  side  but  two. 

The  first  on  the  right  side  is  denominated  Superior  or 
Superficial  Cardiac  Nerve.  It  generally  arises  by  several 
fine  threads,  which  unite  into  one  delicate  cord  that  passes 
down  by  the  side  of  the  common  carotid.  When  it  has 
arrived  on  a line  with  the  middle  ganglion,  it  sends  a 
twig  to  the  thyroid  plexus,  and  another  that  communicates 
with  a twig  from  the  par  vagum,  which  continues  down- 
wards on  the  carotid  artery.  After  passing  beyond  the 
ganglion,  it  divides  into  several  branches,  which  unite 
themselves  to  branches  of  the  recurrent  nerve  that  are 
going  to  the  middle  ganglion. 

The  second,  which  is  denominated  the  Middle  Cardiac , 
the  Great  Cardiac , or  the  Deep  Cardiac , is  the  largest  of 
the  three.  It  arises  from  the  Middle  Cervical  or  Thyroid 
Ganglion , by  five  or  six  fine  fibrils,  which  finally  form 
one,  that  passes  before  and  across  the  subclavian;  and  at 
that  place,  as  well  as  lower  down,  it  receives  twigs  from 
the  par  vagum:  below’  this,  it  is  joined  by  a considerable 
twig  from  the  recurrent,  and  terminates  in  the  Cardiac 
Plexus , to  which  it  contributes  largely. 

The  third  cardiac  nerve  of  the  right  side  is  called  the 
Inferior  or  the  Small  Cardiac  Nerve.  It  originates  from 
the  third,  or  lower  cervical  ganglion,  by  many  fibrils  which 
unite  into  a smaller  number  that  form  a plexus.  It  crosses 
behind  the  subclavian,  and  proceeds  on  the  outside  of  the 
Arteria  Innominata  to  the  curve  of  the  aorta;  continuing 
between  it  and  the  pulmonary  artery,  to  the  anterior  co- 


3 55 


Branches  of  the  Sympathetic . 

ronary  plexus.  In  this  course  it  receives  several  fibres 
from  the  recurrent  and  the  par  vagum. 

On  the  left  side  the  first  cardiac  nerve  arises  from  the 
upper  ganglion.  The  second  derives  its  origin  from  the 
two  lower  ganglions. 

The  left  superior  or  superficial  cardiac  nerve  arises  like 
the  right,  by  many  distinct  fibres,  and  proceeds  down- 
wards in  the  same  way.  It  descends  between  the  carotid 
and  the  subclavian,  and  when  it  has  arrived  at  the  place 
where  they  originate  from  the  aorta,  it  divides  into  a 
great  number  of  small  ramifications.  Some  pass  before 
the  aorta,  either  to  join  the  branches  of  the  inferior  cardiac, 
or  to  unite  with  the  cardiac  branches  of  the  left  nerve  of 
the  par  vagum.  The  others  proceed  behind  the  aorta,  and 
enter  into  the  common  cardiac  plexus. 

The  second  cardiac  nerve  of  the  left  side  may  be  called 
the  Great  Left  Cardiac , and  has  a double  origin  as  above 
mentioned.  The  principal  branch  in  its  composition  arises 
from  the  lowest  cervical  ganglion,  and  passes  behind  the 
transverse  portion  of  the  subclavian  artery.  Where  the 
inferior  thyroid  arises  from  the  subclavian,  this  branch 
receives  a considerable  number  of  ramifications,  which 
arise  from  the  upper  ganglion,  and  are  interwoven  with 
each  other  before  they  unite  to  it.  It  passes  behind  the 
curve  of  the  aorta,  and  terminates  in  the  great  cardiac 
plexus,  which  it  particularly  contributes  to  form.  Here  it 
is  joined  by  many  fibres  from  the  par  vagum. 

The  Cardiac  Plexus 

Is  situated  principally  behind  the  curve  of  the  aorta,  at  a 
small  distance  above  the  heart.  It  commences  as  high  as 
the  origin  of  the  Arteria  Innominata,  and  extends  down- 
wards to  the  bifurcation  of  the  pulmonary  artery. 

As  has  been  already  mentioned,  it  is  principally  com- 
posed of  branches  from  the  middle  cardiac  nerve  of  the 


356  Plexus  formed  by  the  Nerves  of  the  Heart. 

right  side,  and  the  inferior  cardiac  nerve  of  the  left;  but  it 
receives  branches  from  the  superior  cardiac  of  the  left, 
and  sometimes  of  the  right  side.  Some  fibres  of  the 
inferior  cardiac  of  the  right  are  also  united  to  it. 

Many  branches  proceed  from  this  plexus. 

A small  number  pass  upon  the  aorta,  and  seem  to  enter 
into  its  texture.* 

Some  of  them  also  combine  with  the  ramifications  of 
the  Par  V agum  in  the  anterior  pulmonary  plexus. 

The  majority  proceed  to  the  basis  of  the  heart,  near 
the  origin  of  the  pulmonary  artery  and  the  aorta,  and 
constitute  the  proper  nerves  of  that  organ.  They  accom- 
pany the  coronary  arteries,  and  are  so  arranged  around 
them  that,  by  some  anatomists,  they  have  been  said  to 
form  plexuses,  which  have  been  denominated  Coronary. 

The  sympathetic  nerve,  as  has  been  stated  above, 
proceeds  from  the  ganglion,  called  the  Lower  Cervical , 
or  the  First  1 horacic , before  the  neck  of  the  first  rib.  It 
continues  to  descend,  in  the  same  direction,  along  the 
spine,  exterior  to  the  pleura,  to  the  inferior  part  of  the 
thorax.  Near  the  head  of  each  rib  it  forms  a ganglion, 
which  unites  with  the  intercostal  nerve  behind  it,  by  two 
branches,  and  thus  forms  an  indirect  communication  with 
the  medulla  spinalis. 

From  several  of  the  uppermost  of  these  ganglions,  small 
twigs  proceed  to  the  pulmonary  plexus,  and  also  to  the 
great  trunk  of  the  aorta,  below  the  curve,  forming  a spe- 
cies of  network,  or  plexus,  upon  it. 

From  the  ganglions  near  the  heads  of  the  fifth  and 
sixth  ribs,  and  from  four  or  five  of  the  ganglions  which 
succeed  them,  small  nerves  arise,  which  proceed  down- 
wards on  the  sides  of  the  bodies  of  the  vertebra;,  and  unite 
into  one  trunk  that  is  denominated  the  Splanchnic  Nerve , 
because  it  is  distributed  to  the  viscera  of  the  abdomen. — 
This  nerve  proceeds  behind  the  crus  of  the  diaphragm,  on 

* It  has  been  asserted,  that  some  of  the  anatomists  of  Paris  have 
traced  these  neryes  on  the  aorta,  to  a great  distance  from  the  heart. 


Sympathetic  Nerve , and  its  Splanchic  Branches . 357 

its  respective  side,  into  the  abdomen.  A second  and  smaller 
nerve,  of  the  same  destination,  called  the  Lesser  Splanch- 
nic Nerve,  arises  lower  down,  from  two  or  three  of  the 
lowermost  dorsal  ganglions,  and  penetrates  separately 
into  the  cavity  of  the  abdomen:  it  then  generally  divides 
into  two  branches,  one  of  which  unites  to  the  great 
splanchnic  nerve,  and  the  other  proceeds  to  the  renal 
plexus , soon  to  be  described. 

As  soon  as  the  great  splanchnic  nerve  has  entered  the 
abdomen,  it  divides  into  many  branches,  which  commonly 
form  small  ganglions  on  each  side  of  the  coeliac,  but  above 
it.  These  ganglions  are  generally  contiguous;  but  some- 
times they  are  at  a small  distance  from  each  other,  and 
united  by  nerves.  They  are,  however,  commonly  spoken  of 
as  one,  and  called  the  semilunar  ganglion.  They  are 
of  irregular  forms,  and  very  different  from  each  other  in 
size,  as  well  as  form.  Those  formed  by  the  splanchnic 
nerve  on  one  side  are  sometimes  different  from  those  on 
the  other. 

From  this  assemblage  of  ganglions  proceed  many  small 
nerves,  which  are  woven  together  so  as  to  form  a network 
denominated  the  solar  plexus. 

This  plexus  is  situated  anterior  to  the  spine  and  the 
crura  of  the  diaphragm;  behind  the  stomach,  and  above 
the  pancreas;  and  is  extended  upon  the  coeliac  and  superior 
mesenteric  arteries.  Some  ramifications  from  the  par  va- 
gum  and  the  phrenic  also  join  it. 

The  lower  part  of  the  solar  plexus,  which  surrounds 
more  immediately  the  coeliac  artery,  is  termed  the  Cceliac 
Plexus.  From  it  networks  of  nerves  extend  upon  the  great 
branches  of  the  artery  to  the  organs  which  they  go  to. 

They  extend  to  the  stomach  (although  it  is  supplied 
by  the  par  vagum)  along  the  superior  coronary  or  gastric 
branch  of  the  hepatic;  and  the  fibres  in  their  composition 
being  spread  upon  the  coats  of  the  stomach,  unite  with 


358  Arrangement  of  the  Nerves  of  the 

the  branches  of  the  par  vagum,  which  are  also  spread 
upon  them. 

A similar  network,  denominated  the  Hepatic  Plexus, 
extends  upon  the  Hepatic  Artery , and  from  it  to  the  V ena 
Portarum;  and  accompanies  those  vessels  into  the  sub- 
stance of  the  liver.  It  also  sends  branches  to  the  biliary- 
duct  and  gall  bladder;  to  the  stomach  by  the  arteria  gas- 
trica  dextra;  and  to  the  omentum. 

The  Splenic  Artery  is  invested  by  a similar  but  smaller 
arrangement  of  nerves,  denominated  the  Splenic  Plexus. 
In  its  course  to  the  spleen,  this  plexus  sends  some  nerves 
to  the  pancreas;  and  also  to  the  stomach  and  omentum, 
with  the  left  gastric  artery. 

The  superior  mesenteric  artery  is  surrounded  by  a 
network,  which  extends  to  it  directly  from  the  solar 
plexus,  and  is  the  largest  of  all  which  proceed  from  that 
plexus.  The  Mesenteric  Plexus  at  first  nearly  surrounds 
the  artery,  and  proceeds  with  it  between  the  laminae  of 
the  mesentery.  In  this  course  it  sends  branches,  with  the 
arteria  colica  dextra,  to  the  transverse  portion  of  the  colon. 
Between  the  laminae  of  the  mesentery,  it  sends  ramifica- 
tions with  all  the  branches  of  the  artery,  to  the  small  in- 
testines generally;  to  the  coecurn,  and  the  right  portion  of 
the  colon;  as  well  as  to  the  mesenteric  glands. 

From  the  lower  part  of  the  solar  plexus  a network 
proceeds,  on  the  front  of  the  aorta,  to  the  inferior  mesen- 
teric artery,  and  surrounds  it.  Nerves  from  this  plexus 
accompany  the  artery  to  the  left  portion  of  the  colon  and 
the  rectum.  Some  of  their  ramifications  combine  with 
those  of  the  hypogastric  plexus. 

The  Emulgent  Artery  is  attended  by  nerves,  which 
are  arranged  like  a network  on  its  anterior  and  posterior 
surfaces,  and  are  denominated  the  Renal  Plexus.  They 
are  derived  from  the  solar  plexus,  and  frequently  contain 
small  ganglions.  They  proceed  with  the  artery  to  the 


Abdominal  Viscera. 


359 


fissure  of  the  kidney,  and  are  distributed  with  its  different 
ramifications,  in  the  substance  of  the  organ. 

Some  branches  pass  from  them  to  the  renal  gland  with 
the  capsular  artery. 

Before  the  renal  plexus  arrives  at  the  kidney,  it  sends 
off,  from  its  inferior  part,  some  few  fibres,  which,  after 
joining  some  others  from  one  of  the  lumbar  nerves,  ac- 
company the  spermatic  arteries,  and  are,  therefore,  called 
the  Spermatic  Plexus.  In  the  male,  these  fibres  proceed 
through  the  abdominal  ring,  and  many  of  them  go  to  the 
testis,  but  they  are  followed  with  great  difficulty,  on 
account  of  their  small  size. 

In  the  female,  they  go  to  the  ovary  and  the  fallopian  tube. 

From  the  great  plexuses  above,  a small  network  con- 
tinues downwards  on  the  aorta,  receiving  fibres  from  the 
intercostals  on  each  side;  at  the  great  bifurcation  of  the 
aorta  it  divides,  and  is  joined  on  each  side  by  many  rami- 
fications from  the  third  dorsal  nerves,  which  thus  form  a 
plexus  of  considerable  extent,  that  sends  nerves  to  the 
bladder,  rectum,  and  vesicular  seminales  in  males;  and  to 
the  uterus  and  vagina,  as  well  as  the  bladder  and  rectum, 
in  females.*  This  is  called  the  Hypogastric  Plexus. 

The  plexuses  above  mentioned  are  derived  from  the 
splanchnic  nerve,  which  came  off  from  the  Sympathetic 
in  the  thorax. 

The  sympathetic  nerve,  after  giving  off  the  lesser 
splanchnic,  is  diminished  in  size,  and  approaches  nearer 
to  the  bodies  of  the  vertebras.  It  passes  through  the  crura 
of  the  diaphragm,  and  then  proceeds  forwards  and  down- 
wards upon  the  spine,  between  the  tendinous  crura  of 
the  diaphragm  and  psoas  muscle;  near  the  vena  cava  on 
the  right  side,  and  the  aorta  on  the  left.  In  this  course,  it 

* Although  the  testicle  receives  nerves  which  are  derived  from  the 
Sympathetic,  the  penis  and  other  external  parts  of  the  organs  of  ge- 
neration do  not:  the  nerves  which  accompany  the  pudic  artery  being 
derived  from  those  which  unite  to  form  the  great  Sciatic. 


360  Termination  of  the  Sympathetic  Nerve. 

generally  receives  one  or  two  small  cords  from  the  anterior 
branch  of  each  of  the  lumbar  nerves:  these  cords  proceed 
downwards  and  forwards,  between  the  bodies  of  the  ver- 
tebrae and  the  psoas  muscle,  and  a ganglion  is  generally- 
formed  at  the  place  where  they  join  the  nerve. 

In  its  descent  on  the  lumbar  vertebrae,  the  Sympathetic 
sends  off  several  nerves  that  unite  to  the  network  which 
descends  on  the  aorta  from  the  plexus  above.  After 
passing  over  the  lumbar  vertebrae,  it  descends  into  the 
pelvis,  close  to  the  sacrum,  on  the  inner  side  of  the  great 
foramina:  here  it  also  forms  ganglions,  and  communicates 
with  the  sacral  nerves,  and  likewise  with  the  hypogastric 
plexus.  It  terminates  on  the  os  coccygis,  where  its  minute 
fibres  join  those  of  the  opposite  side. 


/ 


SYSTEM  OF  ANATOMY. 


PART  XI. 


OF  THE  ABSORBENT  VESSELS. 

The  absorbent  vessels  are  small  transparent  tubes,  of  a 
delicate  structure,  which  exist  in  considerable  numbers  in 
almost  every  part  of  the  body. 

These  tubes  originate  upon  the  surfaces  of  all  the 
cavities  of  the  body;  and  of  the  cellular  membrane,  in  all 
the  various  parts  into  which  it  penetrates;  upon  the  inter- 
nal surface  of  the  stomach  and  the  intestines;  and  probably 
upon  the  skin. 

Those  which  originate  in  the  Lower  Extremities  and 
the  Cavity  of  the  Abdomen , unite  and  form  a large  trunk 
called  the  thoracic  duct,  which  proceeds  through  the 
thorax,  and  terminates  in  the  left  Subclavian  Vein , at  its 
junction  with  the  Internal  Jugular.  Those  of  the  Left 
Upper  Extremity , the  Left  Side  of  the  Head , and  the  con- 
tiguous parts,  form  a trunk  which  terminates  in  the  same 
place.  While  the  remaining  absorbents,  or  those  of  the 
Right  Upper  Extremity , and  the  Right  Side  of  the  Head, 
also  form  a trunk,  which  terminates  in  the  correspond- 
ing part  of  the  Right  Subclavian  V ein. 

The  absorbent  vessels  of  the  middle  size,  which  arise 
from  the  union  of  the  small  vessels,  and  unite  to  form 
the  larger;  in  their  progress  to  these  large  vessels,  pass 
Vql.  II.  2 Z 


362  Structure  of  the  Absorbent  Vessels . 

through  certain  bodies  which  have  been  denominated 
Conglobate  Glands , and  may  be  considered  as  appendages 
of  the  absorbent  system. 

The  absorbent  vessels  are  composed  of  two  coats,  which 
are  thin,  but  dense  and  firm,  and  also  elastic.  The  coats  of 
the  thoracic  duct  may  be  separated  from  each  other.  The 
internal  surface  of  the  exterior  coat  is  fibrous.  The  inter- 
nal coat  is  a delicate  but  strong  membrane. — There  is 
great  reason  to  believe  that  the  above  mentioned  fibres 
are  muscular,  or  at  least  irritable:  for  the  absorbent  ves- 
sels have  been  observed,  by  Haller,  to  contract  upon  the 
application  of  strong  sulphuric  acid.  They  have  also  been 
observed  to  propel  their  contents  with  considerable  rapi- 
dity, by  their  own  contraction,  independent  of  pressure,  or 
of  motion  communicated  by  any  other  body. 

Bloodvessels  are  sometimes  observable  in  the  coats  of 
the  larger  absorbents,  in  injected  subjects.  The  vascularity 
of  these  tubes  may  also  be  inferred  from  the  inflammation 
which  frequently  takes  place  in  them. 

Nerves  have  not  been  traced  into  their  texture;  but  the 
absorbents  seem  to  be  painful  when  they  are  inflamed, 
and,  therefore,  it  is  probable  that  they  are  supplied  with 
nerves. 

The  absorbent  vessels  are  very  generally  supplied  with 
valves,  which  are  much  more  numerous  in  some  of  them 
than  in  others;  and  are  different  in  their  number,  in  the 
same  vessels,  in  different  subjects. 

Very  frequently  there  are  several  valves  in  the  course 
of  an  inch:  sometimes  a valve -will  not  appear  in  the 
course  of  several  inches.  In  the  Thoracic  Duct , the  num- 
ber of  valves  is  very  different  in  different  subjects.  These 
valves  are  folds  or  plaits  of  the  internal  membrane,  and 
are  of  a semi-circular  form.  There  are  commonly  two  of 
them  together,  originating  from  opposite  sides  of  the 
vessel. 

The  absorbents  are  generally  somewhat  dilated  on  the 


Commencement  of  the  Absorbents . 363 

side  of  the  valve  which  is  next  to  their  termination,  and 
this  occasions  their  knotted  appearance  when  they  are 
injected.  The  object  of  this  valvular  structure  seems  to  be 
the  prevention  of  retrograde  motion  of  the  contained  fluid, 
in  consequence  of  lateral  pressure. 

Where  the  different  trunks  of  the  absorbents  open  into 
the  veins,  there  are  one  or  two  valves  to  prevent  the  re- 
gurgitation of  the  blood  into  them. 

The  valves  of  course  prevent  the  injection  of  the 
branches  of  these  vessels  from  their  trunks. — In  some 
animals  the  valves  have  sometimes  been  ruptured,  or 
forced  back;  and  the  absorbents  have  been  injected  in  a 
retrograde  direction.  There  are  but  two  or  three  instances 
upon  record  where  this  has  been  practicable  in  the  Human 
Subject . 

In  consequence  of  the  impracticability  of  injecting  the 
small  branches  from  the  larger,  the  absorbent  vessels 
cannot,  generally,  be  demonstrated  at  their  commence- 
ment, or  origin.  It  is,  however,  to  be  observed,  that 
the  iacteals,  or  Absorbents  of  the  Intestines , appear 
no  way  different  from  other  absorbents;  and  they  have 
been  seen  distended  with  chyle,  from  their  commence- 
ment, in  certain  subjects  who  had  died  suddenly.  Their 
origins  have  been  described  very  differently  by  different 
observers. 

Mr.  Cruikshank  describes  them  as  originating  on  the 
surfaces  of  the  villi,  by  a number  of  very  small  radiated 
branches  with  open  orifices;  which  branches  soon  unite 
to  form  a trunk. 

Lieberkuhn  believed  them  to  commence  in  the  form  of 
an  ampullula. — See  page  105  of  this  volume. 

The  second  Monro  also  believes  that  the  absorbents 
begin  by  very  small  tubes,  with  open  orifices,  in  several 
species  of  fish.* 

* See  his  work  on  the  Structure  and  Physiology  of  Fishes,  p.  34. 


364 


Conglobate  Glands. 

It  is  stated  by  Dr.  Soemmering,  upon  the  authority  of 
Haase,  a German  anatomist,  that  when  mercury  is  forced 
backwards  in  the  absorbent  vessels  of  the  foot  and  the 
heart,  it  has  sometimes  escaped  on  the  surfaces  of  those 
parts.  The  probable  inference  from  these  facts  is,  that 
those  vessels  originate  by  open  oiifices  on  the  surfaces 
of  the  heart  and  foot. 

The  bodies  connected  with  the  absorbent  vessels,  which 
are  called  Conglobate  Glands,  are  generally  of  a roundish, 
or  irregular  oval  form,  and  somewhat  flattened.  They 
are  of  various  sizes,  from  two  lines  in  diameter  to  more 
than  twelve.  Their  colour  is  frequently  whitish,  but  some- 
times it  is  slightly  inclined  to  red.  They  are  invested  with 
a covering  of  cellular  membrane,  which  appears  like  a 
membranous  coat;  and  they  are  connected  to  the  contigu- 
ous parts  by  a loose  cellular  substance.  When  the  absorb- 
ent vessels  connected  with  these  bodies  approach  near  to 
them,  they  divide  into  a number  of  ramifications,  most 
of  which  enter  into  the  substance  of  the  gland,  while 
some  of  them  run  over  it.  On  the  opposite  side  of  the 
gland  a number  of  branches  go  out,  which  unite  and 
form  trunks  similar  to  those  which  entered  the  gland. 
The  vessels  which  enter  the  gland  are  called  Vasa  Infe- 
rentia , and  those  which  go  out  of  it  Vasa  efferentia. 

These  vessels  are  generally  much  convoluted  in  the 
substance  of  the  glands,  so  that  those  bodies  sometimes 
appear  like  a mere  convolution  of  absorbent  vessels. 
There  has  been  much  diversity  of  sentiment  respecting 
the  structure  of  these  organs.* 

The  absorbent  vessels,  in  the  different  parts  of  the 

* Mr.  Abernethy  states,  that  the  mesenteric  gland  of  the  Whale 
consists  of  large  spherical  bags,  into  which  a number  of  the  lacteals 
open.  Numerous  bloodvessels  are  ramified  on  the  surfaces  of  these 
cysts;  and  injection  passes  from  them  into  the  cyst.  He  also  found 
cells  in  the  glands  of  the  absorbent  vessels,  in  the  groin  and  the 
axilla  of  the  horse.— -See  Philosophical  Transactions,  for  1796,  Part  I. 


Fluid  Contained  in  the  Absorbents.  365 

body,  generally  contain  fluids  resembling  those  which  are 
found  in  those  parts.  Mr.  Hewsori  opened  the  large 
absorbents  in  many  living  animals  of  different  kinds,  and 
found  that  they  contained,  a transparent  fluid,  which  co- 
agulated when  exposed  to  the  air. 

The  arrangement  of  these  vessels  resembles  that  of  the 
veins  in  several  respects.  Many  of  them  are  superficial; 
but  there  are  also  deep-seated  absorbents  which  accom- 
pany the  bloodvessels. 


366 


CHAPTER  I. 

OF  THE  ABSORBENTS  OF  THE  LOWER  EXTREMITIES,  THE 
ABDOMEN,  AND  THE  THORAX. 

UNDER  this  head  are  arranged  the  ramifications  of  all 
the  vessels  which  unite  to  form  the  Thoracic  JDuct. 

I 

SECTION  I. 

Of  the  Absorbents  of  the  Lower  Extremities. 

These  'absorbents,  like  the  veins,  are  superficial  and 
deep-seated.  The  Superficial  lie  in  the  cellular  membrane, 
very  near  the  skin;  and  form  an  irregular  network  which 
extends  over  the  whole  limb.  They  are,  however,  most 
numerous  on  the  internal  side. 

The  Deep-seated  accompany  the  arteries  like  the  veins, 
and  there  are  two  at  least  to  each  artery. 

The  Superficial  Absorbents 

Have  been  injected  from  the  toes  so  as  to  form  a network, 
which  occupies  the  upper  surface  of  the  foot.  They  have 
also  been  injected  in  a similar  manner  on  the  sole.  Those 
on  the  upper  surface  of  the  foot  generally  proceed  up- 
ward on  the  anterior  and  inner  side  of  the  leg;  but  some 
of  them  pass  on  the  external  side  of  it.  Those  on  the  sole 
are  continued  on  the  back  of  the  leg,  but  communicate 
very  frequently  with  the  anterior  vessels.  Some  of  the 
absorbents  from  the  outside  of  the  foot  and  leg  enter  into 
some  of  the  popliteal  glands,  soon  to  be  described;  but  they 


Absorbents  of  the  Lower  Extremity.  367 

are  not  numerous;  and  the  principal  number  continues  up 
to  the  glands  of  the  groin.  The  absorbents  which  originate 
on  the  surface  of  the  thigh,  as  well  as  those  which  pass 
over  it  from  below,  incline  gradually  along  the  anterior 
and  posterior  surface,  to  the  internal  side  of  it;  on  which 
they  proceed,  in  great  numbers,  and  very  near  to  each 
other,  to  the  inguinal  glands.  Superficial  absorbents  pro- 
ceed also  from  the  buttock  and  lower  part  of  the  back, 
from  the  lower  part  of  the  abdomen,  the  perineum,  and 
the  exterior  of  the  genital  organs,  to  these  glands. 

The  Deep-seated  Absorbents 
Are  named  from  the  arteries  they  accompany. 

The  Anterior  Tibial  Absorbents . 

The  anterior  tibial  artery  is  generally  attended  by  one 
which  comes  with  it  from  the  sole,  and  by  another  which 
commences  on  the  upper  surface  of  the  foot.  The  first 
mentioned  absorbent  continues  with  the  artery.  The  last, 
often  passes  through  an  aperture  in  the  interosseal  liga- 
ment, about  one  third  of  the  distance  from  the  ankle  to 
the  knee,  and  accompanies  the  fibular  artery,  while  the  an- 
terior tibial  artery  is  joined  by  other  absorbents  about  the 
same  place.  In  some  instances  a small  absorbent  gland  oc- 
curs in  this  course,  at  a short  distance  below  the  knee. 

The  Posterior  Tibial  Absorbents 

Have  been  injected  from  the  under  side  of  the  toes.  They 
accompany  the  ramifications  on  the  sole  of  the  foot;  and 
after  uniting,  continue  with  the  main  trunk  up  the  leg, 
where  they  enter  into  the  popliteal  glands. 

The  Peroneal  Absorbents  arise  also  from  the  sole  of  the 
foot,  and  its  external  side.  They  accompany  the  peroneal 


368  Absorbents  of  the  Lower  Extremity . 

artery,  and  terminate  in  the  popliteal  glands,  which  re- 
ceive also  the  absorbents  from  the  knee  and  ham. 

From  these  glands  four  or  five  absorbent  vessels  proceed, 
which  accompany  the  great  bloodvessels  of  the  lower  ex- 
tremity; and,  proceeding  with  them  through  the  aperture 
in  the  tendon  ol  the  adductors,  continue  upwards  until 
they  enter  some  of  the  glands  of  the  groin. 

The  glands  of  the  ham  and  groin,  which  are  so  inti- 
mately connected  with  the  absorbents  of  the  lower  extre- 
mity, are  very  different  from  each  other. 

The  Popliteal  Glands , or  those  of  the  Ham,  are  but 
three  or  four  in  number,  and  very  small  in  size.  They 
are  generally  deep-seated,  and  very  near  the  artery. 

The  Inguinal  Glands  vary  in  number,  from  eight  to 
twelve  or  more.  They  are  superficial  and  deep-seated. 
The  superficial  communicate  principally  with  the  superfi- 
cial absorbents.  The  lowermost  of  them  are  at  some  dis- 
tance below  Pou part’s  ligament,  and  the  uppermost  are 
rather  above  it.  They  are  exterior  to  the  fascia  of  the 
thigh.  Their  number  is  generally  six  or  eight,  while  that 
of  the  deep-seated  is  but  three  or  four. 

The  superficial  absorbents  from  below,  approach  very 
near  to  each  other,  and  enter  these  glands.  They  are 
commonly  distributed  among  three  or  four  of  the  lower- 
most; but  some  of  them  pass  by  these,  and  proceed  to 
one  that  is  higher  up;  and  sometimes  there  are  absorbent 
vessels  which  pass  to  the  abdomen  without  entering  into 
any  of  the  glands  of  the  groin. 

The  deep-seated  absorbents  pass  into  the  deep-seated 
glands,  which,  as  has  been  already  observed,  are  but  few, 
and  lie  very  near  the  artery  under  the  fascia  of  the  thigh. 
The  two  sets  of  glands  are  connected  to  each  other  by 
many  absorbent  vessels  that  pass  between  them.  The 
vessels  which  finally  go  out  of  these  glands  are  con- 
siderably less  in  number  than  those  which  enter  into 
them.  They  proceed  under  Poupart’s  ligament,  and,  in 


369 


Inguinal  and  External  Iliac  Glands. 

some  instances,  a large  proportion  of  them  pass  through 
three  glands  which  lie  below  this  ligament,  and  are  often 
so  arranged,  that  they  lie  on  each  side  of  the  great  femoral 
vessels,  and  above  them.  One  very  frequently  is  found  on 
the  inside  of  the  femoral  vein,  in  the  vacuity  between  it 
and  the  internal  part  of  the  ligament.  All  the  absorbents 
of  the  lower  extremity,  however,  do  not  enter  these 
glands.  Some  pass  along  with  the  great  vessels  and  enter 
other  glands  near  the  margin  of  the  pelvis.  Some  also 
descend  a short  distance  into  the  pelvis,  and  unite  with 
vessels  that  are  passing  from  the  pelvis  to  the  plexus  and 
the  srlands  that  surround  the  external  iliac. 

The  absorbents  which  proceed  from  the  glands  last 
mentioned,  joined  to  those  which  pass  under  Poupart’s 
ligament,  without  entering  these  glands;  and  some  which 
come  from  the  pelvis;  form  a large  plexus,  which  almost 
surrounds  the  external  iliac  vessels,  and  contains  many 
glands. 

These  Exiernal  Iliac  Glands  vary  in  their  number  from 
six  to  ten  or  twelve.  They  lie  on  the  side  of  the  pelvis,  in 
the  course  of  the  external  iliac  vessels,  and  some  of  them 
are  of  considerable  size.  These  glands  and  the  plexus  of 
absorbents,  extend  in  the  track  of  the  iliac  vessels,  to  the 
first  lumbar  vertebra.  In  this  course  they  are  joined  by 
the  plexus  which  comes  from  the  pelvis;  and  soon  after 
they  arrive  at  the  Lumbar  Glands , which  form  a very  large 
assemblage,  that  extends  from  the  bifurcation  of  the  aorta 
to  the  crura  of  the  diaphragm. 

These  glands  lie  irregularly,  on  the  aorta  and  the  vena 
cava,  and  the  lumbar  vertebrae.  Most  if  not  all  the  ab- 
sorbents above  mentioned  pass  through  some  of  them; 
and  from  the  union  of  these  absorbents,  some  of  the  great 
branches,  which  unite  to  form  the  thoracic  duct,  are 
derived. 

In  this  course  from  the  thigh  to  the  lumbar  glands, 
these  absorbent  vessels  are  joined  by  several  others.  The 

N ol.  II.  3 A 


370  Absorbents  of  the  Testicles , &c. 

Superficial  Absorbents  of  the  scrotum  commonly  enter 
into  the  upper  inguinal  glands,  and  thus  unite  to  the  great 
body  of  absorbents. 

The  Absorbents  of  the  Testicles  originate  in  the  body, 
and  the  coats  of  the  testicle,  and  in  the  epididymis;  and 
are  remarkably  large  and  numerous.  They  proceed  along 
the  spermatic  cord,  through  the  abdominal  ring,  to  the 
lumbar  glands.  These  vessels  are  remarkable  for  the  little 
communication  the}  have  with  each  other. 

The  Deep-seated  Absorbents  of  the  Scrotum  accompa- 
ny the  absorbents  of  the  testicle  to  the  lumbar  glands; 
but  those  which  are  superficial  enter  the  upper  inguinal 
glands. 

The  Absorbents  of  the  Penis  are  also  deep-seated  and 
superficial.  The  deep-seated  arise  from  the  body  of  the 
penis,  and  accompany  the  internal  pudic  artery  into  the 
pelvis.  The  superficial  absorbents  arise  from  the  prepuce, 
and  pass  along  the  dorsum  of  the  penis.  There  are  fre- 
quently several  trunks  which  receive  branches  from  the 
lower  surface  of  the  penis  in  their  course.  At  the  root  of 
the  penis  they  generally  separate  to  the  right  and  left,  and 
pass  to  the  glands  on  the  respective  sides. 

Tr  fe  males,  the  absorbents  of  the  interior  of  the  clitoris 
accompany  the  internal  pudic  artery.  Some,  which  arise 
about  the  vagina,  pass  through  the  abdominal  ring  with 
the  round  ligament;  and  others  proceed  to  the  inguinal 
glands. 


Absorbents  of  the  Pelvis  and  the  Kidneys . 371 


SECTION  II. 

Of  the  Absorbents  of  the  Abdomen  and  Thorax. 

The  Absorbents  of  the  lower  portions  of  the  parietes  of 
the  Abdomen  and  the  Pelvis  unite  into  trunks  that  follow 
the  epigastric,  and  the  circumflex  iliac,  as  well  as  the  lum- 
bar and  sacral  arteries,  &c.  They  proceed  to  some  of  the 
glands  which  are  in  the  groin;  or  in  the  external  iliac, 
the  hypogastric,  or  some  of  the  contiguous  plexuses. 

The  Absorbents  of  the  Womb  are  extremely  numerous; 
and,  in  the  gravid  state,  are  very  large.  Those  which  are 
on  the  neck  and  anterior  part  of  the  uterus,  join  the  hypo- 
gastric plexus.  Those  which  are  on  the  posterior  part  of 
the  body,  accompany  the  spermatic  vessels. 

The  Absorbents  of  the  bladder  pass  to  small  glands  on 
its  lateral  and  inferior  parts,  and  finally  join  the  hypo- 
gastric plexus. 

The  Absorbents  of  the  Rectum  are  of  considerable  size. 
They  pass  through  glands  that  lie  upon  that  intestine",  and 
unite  with  the  lumbar  plexus. 

The  Absorbents  of  the  Kidney  are  superficial  and  deep- 
seated.  They  are  very  numerous,  but,  in  a healthy  state 
of  the  parts,  are  discovered  with  difficulty.  Cruikshank 
describes  them  as  they  appeared,  filled  with  blood,  in  con- 
sequence of  pressing  upon  the  kidney  when  its  veins 
were  full  of  blood.  Mascagni  did  not  inject  the  superficial 
vessels  with  mercury;  but  describes  them  as  they  appear- 
ed when  filled  with  colourless  size,  after  he  had  injected 
the  bloodvessels  of  the  organ  with  the  coloured  fluid. — - 
The  deep-seated  absorbents  pass  out  of  the  fissure  of  the 
kidney  with  the  bloodvessels,  and  unite  with  the  superfi- 
cial; they  proceed  to  the  lumbar  plexus,  and  pass  into 
different  glands. 

Absorbent  vessels  can  be  proved  to  proceed  from  the 


372  Lac  teals,  or  Absorbents  of  the  Intestines. 

pelvis  of  the  kidney,  and  the  ureters,  by  artifices  analogous 
to  those  above  mentioned. 

The  Glandule  Renales  are  also  supplied  with  absorbents, 
which  are  numerous  in  proportion  to  the  size  of  the 
organs.  They  commonly  join  those  of  the  kidney. 

The  Absorbents  of  the  Intestines 

Have  generally  been  called  LACTEALS,  from  the  white 
colour  of  the  chyle  which  they  contain:  but  there  seems 
no  reason  for  believing  that  they  are  different  in  their 
structure  and  nature  from  the  absorbents  in  other  parts  of 
the  body.  A small  number  of  them  appear  as  if  they 
formed  a part  of  the  structure  of  the  intestines,  and  ori- 
ginated from  their  external  surface,  as  they  do  in  other 
parts  of  the  abdomen;  while  the  principal  part  of  them 
are  appropriated  to  the  absorption  of  the  contents  of  the 
cavity  of  the  intestines. 

The  first  mentioned  absorbents  run  between  the  mus- 
cular and  peritoneal  coats,  and  proceed  for  some  distance 
lengthways  on  the  intestine,  while  the  others  proceed 
for  some  distance  within  the  muscular  coat,  with  the  ar- 
teries; and  after  passing  through  it,  continue  between 
the  laminae  of  the  mesentery. 

Branches  of  these  different  absorbents  are  frequently 
united  in  one  trunk;  so  as  to  prove  that  there  is  no 
essential  difference  between  them. 

The  absorbents  which  come  from  the  internal  surface  of 
the  intestines  commence  in  the  villi.  The  manner  in  which 
they  originate  has  been  the  subject  of  considerable  in- 
quiry, as  has  been  stated  in  the  account  of  the  intestines.* 

The  lacteals  or  absorbents  of  the  intestines  are  very 
numerous.  They  pass  between  the  laminae  of  the  mesen- 
tery, to  glands  which  are  also  seated  between  those  laminae. 


* See  page  105. 


Lac  teals,  or  Absorbents  of  the  Intestines.  37  3 

The  number  of  these  glands  is  very  considerable,*  and 
they  are  various  in  size — some  being  very  minute,  and 
others  eight  or  ten  lines  in  diameter.  They  are  generally 
placed  at  a small  distance  from  each  other,  and  are  most 
numerous  in  that  part  of  the  mesentery  which  is  nearest 
to  the  spine.  They  are  almost  always  at  some  distance 
from  the  intestines.  They  appear  to  be  precisely  like  the 
absorbent  glands,  in  other  places. 

These  absbrbent  vessels,  in  their  course  frequently  divide 
into  branches;  which  sometimes  go  to  the  same  gland, 
sometimes  to  different  glands,  and  sometimes  unite  with 
other  absorbent  vessels.  As  they  proceed,  they  frequently 
enlarge  in  size.  When  they  have  arrived  near  the  spine, 
they  frequently  form  three  or  four  trunks,  and  sometimes 
one  or  two;  which  proceed  in  the  course  of  the  superior 
mesenteric  artery,  until  they  have  arrived  near  to  the  aorta. 
Here  they  either  pass  into  the  thoracic  duct,  or  descend 
and  join  the  trunks  from  the  inferior  extremities,  to  form 
the  thoracic  duct.  The  absorbents  of  the  great  intestines  are 
not  equal  in  size  to  those  of  the  small;  but  they  are  nu- 
merous. They  enter  into  glands,  which  are  very  near,  and 
in  some  places,  in  contact  with  the  intestine;  and  are  com- 
monly very  small  in  size.  The  vessels  which  arise  from 
the  csecum,  and  the  right  portion,  as  well  as  the  arch  of 
the  colon,  unite  with  those  of  the  small  intestines;  while 
the  vessels  from  the  left  side  of  the  colon,  and  the  rectum, 
proceed  to  the  lumbar  glands. 

The  absorbents  of  the  intestines  are  frequently  injected 
with  mercury;  but  the  injection  does  not  proceed  to  their 
termination  with  so  much  facility  as  it  does  in  other  ves- 
sels of  the  same  kind.  They  have,  however,  very  often 
been  seen  in  animals,  who  were  killed  for  the  purpose  after 
eating  milk;  and  in  several  human  subjects  who  died  sud- 
denly during  digestion. — The  description  of  the  origin  of 


They  have  been  estimated  between  130  and  150. 


374  Absorbents  of  the  Stomach. 

the  lacteals,  quoted  in  page  106,  from  Mr.  Cruikshank, 
was  taken  from  a subject  of  this  kind,  of  which  an  account 
is  given  in  his  work  on  the  absorbing  vessels,  p.  59. 

It  is  worthy  of  note,  that  in  several  instances,  in  which 
the  lacteals  were  thus  found  distended  with  chyle,  the 
glands  in  the  mesentery  were  also  uniformly  white. 

The  Absorbents  of  the  Stomach 

Are  of  considerable  size,  and  form  three  divisions.  The  ves- 
sels of  the  first  set  appear  upon  both  sides  of  the  stomach, 
and  pass  through  a few  glands  on  the  small  curvature,  near 
the  omentum  minus.  From  these  glands  they  proceed  to 
others,  which  are  larger,  and  which  also  receive  some  of 
the  deep-seated  absorbents  of  the  liver.  The  vessels  from 
these  glands  pass  to  the  thoracic  duct,  near  the  origin  of  the 
caeliac  artery.  The  second  arise  also  on  both  sides  of  the 
stomach,  and  pass  to  the  left  extremity  of  the  great  cur- 
vature to  unite  with  the  absorbents  of  that  side  of  the 
great  omentum.  They  then  proceed  with  the  lymphatics 
of  the  spleen  and  pancreas,  to  the  thoracic  duct.  The  last 
set  pass  off  from  the  right  extremity  of  the  great  curva- 
ture, and  unite  also  with  absorbents  from  the  right  portion 
of  the  omentum.  They  proceed  near  the  pylorus,  and  go 
to  the  thoracic  duct,  with  some  of  the  deep-seated  ab- 
sorbents of  the  liver. 

Although  the  absorbents  of  the  stomach  are  deep-seated, 
as  well  as  superficial,  it  is  a general  sentiment,  that  they 
do  not  contain  chyle  in  the  human  subject;  notwithstand- 
ing chyle  has  been  found  in  the  absorbents  on  the  stomach 
of  dogs,  and  some  other  animals.  It  ought,  however,  to  be 
remembered,  that  Sabatier  has,  in  some  instances,  .seen 
white  lines  on  the  stomach,  which  he  supposed  to  be 
lacteals. 


Absorbents  of  the  Liver . 


375 


The  Absorbents  of  the  Liver 

Are  especially  interesting,  because  they  have  been  more 
completely  injected  than  those  of  any  other  viscus.  They 
are  deep-seated  and  superficial.  The  superficial  it  has  been 
already  observed  admit  of  injection  in  a retrograde  direc- 
tion, and,  therefore,  can  be  exhibited  most  minutely  ra- 
mified. They  communicate  freely  with  each  other,  and 
also  with  the  deep-seated  vessels,  by  their  sntall  ramifi- 
cations; so  that  the  whole  gland  has  been  injected  from  one 
large  vessel. 

The  gland  is  so  large,  that  the  absorbents  of  the  supe- 
rior and  inferior  surfaces  proceed  from  it  in  different  direc- 
tions. 

A large  absorbent  is  generally  found  on  the  suspen- 
sory ligament.  This  is  formed  by  the  union  of  a great 
many  branches  that  arise  both  on  the  right  and  left  lobes, 
but  principally  on  the  right.  It  often  passes  through  the 
diaphragm  at  an  interstice  which  is  anterior  to  the  xiphoid 
cartilage,  and  then  proceeds  through  glands  on  the  anterior 
part  of  the  pericardium. 

Several  absorbents  proceed  to  the  lateral  ligaments  on 
each  side,  and  then  pass  through  the  diaphragm.  Some 
of  these  branches  return  again  into  the  abdomen,  and  the 
others  generally  run  forwards  in  the  course  of  the  ribs, 
and  join  those  which  passed  up  from  the  suspensory  liga- 
ment. The  trunk,  or  trunks,  formed  by  these  vessels,  either 
pass  up  between  the  laminae  of  the  mediastinum,  and  ter- 
minate in  the  upper  part  of  the  thoracic  duct;  or  they 
accompany  the  internal  mammary  arteries,  and  terminate 
on  the  left  side  in  the  thoracic  duct,  and  on  the  right  in 
the  trunk  of  the  absorbents  of  that  side. 

The  Absorbents  on  the  concave  side  of  the  Liver  are  as 
numerous  as  those  on  the  convex  side,  they  are  also  very 


376  Absorbents  of  the  Liver  and  Spleen. 

abundant  on  the  surface  of  the  gall  bladder.  The  greatest 
part  of  them  join  the  deep-seated  vessels. 

The  Deep-seated  Absorbents  proceed  in  considerable 
numbers  from  the  interior  of  the  liver  through  the  portae. 
They  accompany  the  biliary  ducts  and  the  great  blood- 
vessels of  the  organ;  and,  after  passing  through  several 
glands,  near  the  vena  portarum,  terminate  in  the  thoracic 
duct,  near  the  commencement  of  the  superior  mesenteric 
artery. 

Mascagni  states,  that  the  absorbents  of  the  liver  will  be 
distended,  by  injecting  warm  water  into  the  biliary  ducts, 
or  the  vena  portarum. 

He  also  observes,  that  in  those  preparations  in  which 
the  superficial  vessels  are  completely  injected,  in  the  re- 
trograde direction,  the  peritoneal  coat  of  the  liver  appears 
to  be  composed  entirely  of  absorbent  vessels;  and  to  be 
connected  to  the  membrane  within,  by  many  filaments 
which  are  also  absorbent  vessels. 

The  Absorbents  of  the  Spleen 

Are  composed  of  superficial  and  deep-seated  vessels;  but 
they  differ  greatly  from  those  of  the  liver,  in  this  respect, 
that  the  superficial  vessels  are  remarkably  small  in  the 
human  subject. 

Mascagni  however  asserts,  that  when  the  bloodvessels 
of  the  spleen  are  injected  with  size,  coloured  with  ver- 
milion, these  absorbents  will  be  filled  with  colourless  size. 

In  the  spleen  of  the  calf  the  superficial  absorbents  are 
remarkably  large. 

In  the  human  subject  the  superficial  absorbents  of  the 
spleen  proceed  from  the  convex  to  the  concave  surface, 
and  there  communicate  with  the  deep-seated  absorbents, 
which  proceed  from  the  interior  of  the  organ  with  the 
bloodvessels. 

These  Deep-seated  Absorbents  are  very  numerous,  and 


Absorbents  of  the  Pancreas.  Thoracic  Duct.  377 

also  large.  They  accompany  the  splenic  artery;  and  in 
their  course  pass  through  many  glands,  some  of  which 
are  said  to  be  of  a dark  colour.  The  glands  lie  on  the 
splenic  artery,  at  a short  distance  from  each  other.  The 
absorbents  of  the  spleen  receive  the  absorbents  of  the 
pancreas  in  their  course;  they  unite  with  the  absorbents 
of  the  stomach  and  the  lower  surface  of  the  liver,  and 
pass  with  them  to  the  thoracic  duct. 

Little  has  been  latterly  said  by  practical  anatomists 
respecting 

The  Absorbents  of  the  Pancreas. 

Mr.  Cruikshank  once  injected  them  in  the  retrograde  di- 
rection; he  found  that  they  came  out  of  the  lobes  of  the 
pancreas  in  short  branches  like  the  bloodvessels,  and 
passed  at  right  angles  into  the  absorbents  of  the  spleen,  as 
they  accompanied  the  artery  in  the  groove  of  the  pancreas. 

THE  THORACIC  DUCT , 

Or  common  trunk  of  the  absorbent  system,  is  formed 
by  the  union  of  those  absorbent  vessels  which  are  collec- 
ted on  the  lumbar  vertebrae. 

These  vessels,  as  it  has  been  already  observed,  are 
derived  from  various  sources,  viz. 

The  Lower  Extremities;  the  lower  part  of  the  Trunk  of 
the  Body;  the  Organs  of  Generation;  the  Intestines,  with 
the  other  Viscera  of  the  abdomen  and  pelvis,  except  a 
part  of  the  liver.  Their  number  is  proportioned  to  the  ex- 
tent of  their  origin:  for,  with  the  numerous  glands  ap- 
propriated to  them,  they  form  the  largest  absorbent 
plexus  in  the  body,  and  are  spread  over  a considerable 
portion  of  the  aorta  and  the  vena  cava; 

The  manner  in  which  these  vessds  unite  to  form  the 

Von.  II.  3 B 


378  Commencement  of  the  Thoracic  Duct. 

thoracic  duct,  is  very  different  in  different  subjects;  but  in 
a majority  of  cases  it  originates  immediately  from  three 
vessels,  two  of  which  are  the  trunks  of  the  absorbents  of 
the  lower  extremities,  and  the  other  is  the  common  trunk 
of  the  lacteals  and  the  other  absorbents  of  the  intestines. 

These  vessels  generally  unite  on  the  second  or  third 
lumbar  vertebrae;  and,  in  some  instances,  the  trunk  which 
they  form  dilates  considerably,  soon  after  its  commence- 
ment; in  consequence  of  which  it  was  formerly  called  the 
RECEPTACLE  of  the  CHYLE.  At  first  it  lies  behind 
the  aorta,  but  it  soon  inclines  to  the  right  of  it,  so  as  to 
be  behind  the  right  crus  of  the  diaphragm.  In  the  thorax, 
it  appears  on  the  front  of  the  spine,  between  the  aorta  and 
the  vena  azygos,  and  continues  between  these  vessels 
until  it  has  arrived  at  the  fourth  or  third  dorsal  vertebra. 
It  then  inclines  to  the  left,  and  proceeds  in  that  direction 
until  it  emerges  from  the  thorax,  and  has  arisen  above  the 
left  pleura,  when  it  continues  to  ascend  behind  the  inter- 
nal jugular,  nearly  as  high  as  the  sixth  cervical  vertebra:  it 
then  turns  downward  and  forward,  and,  after  descending 
from  six  to  ten  lines,  terminates  in  the  back  part  of  the 
angle  formed  by  the  union  of  the  left  internal  jugular 
with  the  left  subclavian  vein.  Sometimes,  after  rising  out 
of  the  thorax,  it  divides  into  two  branches,  which  unite 
before  they  terminate.  Sometimes  it  divides,  and  one  of 
the  branches  terminates  at  the  above  mentioned  angle,  and 
the  other  in  the  subclavian  vein,  to  the  left  of  it. 

The  orifice  of  the  thoracic  duct  has  two  valves,  which 
effectually  prevent  the  passage  of  blood  into  it  from  the 
vena  cava. 

There  are  sometimes  slight  flexures  in  the  course  of 
the  duct;  but  it  generally  inclines  to  the  left,  in  the  upper 
part  of  the  thorax,  as  above  mentioned;  and  is  then  so 
near  the  left  lamina  of  the  mediastinum,  that,  if  it  be  filled 
with  coloured  injection,  it  can  be  seen  through  that  mem- 


Absorbents  of  the  Lungs.  379 

brane,  when  the  left  lung  is  raised  up  and  pressed  to  the 
right. 

The  duct  sometimes  varies  considerably  in  its  diameter 
in  different  parts  of  its  course.  About  the  middle  of  the 
thorax  it  has  often  been  found  very  small.  In  these  cases 
it  generally  enlarges  in  its  progress  upwards,  and  is  often 
about  three  lines  in  diameter,  in  its  upper  part.  Many 
anatomists  have  observed  it  to  divide  and  to  unite  again, 
about  the  middle  of  the  thorax. 

Absorbents  of  the  Lungs. 

The  absorbents  of  the  lungs  are  very  numerous,  and, 
like  those  of  other  viscera,  are  superficial  and  deep-seated. 

The  large  superficial  vessels  run  in  the  interstices  be- 
tween the  lobuli,  and  therefore  form  angular  figures  of 
considerable  size.  In  successful  injections,  the  vacancies 
within  these  figures  are  filled  up  with  small  vessels,  and 
the  whole  surface  appears  minutely  injected. 

Mascagni  observes,  that  the  superficial  vessels  are  very 
visible  when  any  fluid  has  been  effused  into  the  cavity  of 
the  thorax;  or  when  warm  water  is  injected,  either  into  the 
bloodvessels  of  the  lungs,  or  the  ramifications  of  the 
trachea.  Cruikshank  demonstrated  them  by  inflating  the 
lungs  of  a still  born  child;  in  which  case  the  air  passes 
rapidly  into  them. 

The  deep-seated  absorbents  accompany  the  bloodvessels 
and  the  ramifications  of  the  bronchia.  They  pass  to  the 
dark  coloured  glands,  which  are  situated  on  the  trachea  at 
its  bifurcation;  and  on  those  portions  of  the  bronchiae 
which  are  exterior  to  the  lungs.  The  injection  of  the 
absorbents,  which  pass  to  and  from  these  glands,  seems 
to  prove  that  they  are  of  the  same  nature  with  the  ab- 
sorbent glands  in  general;  notwithstanding  their  colour. 
They  are  numerous,  and  they  vary  in  size;  from  a diameter 
of  two  lines,  to  that  of  eight  or  ten. 


380  Absorbents  of  the  Lungs. 

From  these  glands,  some  of  the  absorbents  of the  left  lung 
pass  into  the  thoracic  duct,  while  it  is  in  the  thorax,  behind 
the  bifurcation  of  the  trachea;  others  proceed  upwards 
and  enter  into  it  near  its  termination;  while  those  of  the 
right  lung  terminate  in  the  common  trunk  of  the  absorb- 
ents of  the  right  side. 


381 


CHAPTER  II. 

OF  THE  ABSORBENTS  OF  THE  HEAD  AND  NECK;  OF  THE 
UPPER  EXTREMITIES,  AND  THE  UPPER  PART  OF 
THE  TRUNK  OF  THE  BODY. 

THE  absorbents  from  the  various  parts  of  the  head  pass 
through  glands,  which  are  situated  on  the  neck,  or  the 
lower  part  of  the  head.  Those  on  the  head  are  the  least 
numerous,  and  also  the  least  in  size.  Some  of  them, 
which  are  generally  small,  lie  about  the  parotid  gland. 
Several  of  them,  which  are  also  small,  are  on  the  occiput, 
below  and  behind  the  mastoid  process.  Sometimes  there 
are  two  or  three  on  the  cheek,  near  the  basis  of  the  lower 
jaw,  about  the  anterior  edge  of  the  masseter  muscle.  Be- 
low the  lower  jaw,  in  contact  with  the  submaxillary  gland 
and  anterior  to  it,  there  are  always  a number  of  these 
glands,  which  are  generally  small,  but  often  swelled  during 
infancy. 

The  Glands  on  the  Neck  are  the  most  numerous.  Many 
of  them  are  within  the  sterno-mastoid  muscle,  and  ac- 
company the  internal  jugular  vein  and  the  carotid  artery 
down  to  the  first  rib.  Many  also  lie  in  the  triangular 
space  between  the  sterno-mastoid  muscle,  the  trapezius, 
and  the  clavicle;  therefore  it  has  been  truly  said  that  the 
glands  of  the  neck  are  more  numerous  than  those  of  any 
other  part,  except  the  mesentery.  They  are  frequently 
called  Glandules  Concatenates.  It  has  already  been  men- 
tioned that  the  various  absorbents,  which  are  connected 
with  these  glands,  unite  on  each  side  into  a trunk,  which 
on  the  left  passes  into  the  thoracic  duct,  and  on  the  right 
into  the  common  trunk  of  the  absorbents  of  that  side. 


382 


Absorbents  of  the  Head  and  Neck. 


SECTION  I. 

Of  the  Absorbents  of  the  Head  and  Neck. 

There  is  the  greatest  reason  to  believe  than  the  brain 
and  its  appendages  are  supplied  with  absorbents  like  the 
other  parts.  Some  of  these  vessels  have  been  discovered 
in  the  cavity  of  the  cranium;  but  very  little  precise  infor- 
mation has  as  yet  been  obtained,  respecting  the  extent, 
or  arrangement  of  the  absorbent  system,  in  this  part  of 
the  body. 

The  absorbents  on  the  exterior  of  the  head  are  as  nu- 
merous as  in  other  parts  of  the  body.  On  the  occiput  they 
pass  down,  inclining  towards  the  ear,  and  continue  be- 
hind it  to  the  side  of  the  neck;  behind  the  ear  they  pass 
through  several  glands.  From  the  middle  or  temporal 
region  of  the  cranium,  they  pass  with  the  carotid  artery 
before  the  ear,  and  enter  some  small  glands  that  lie  on 
the  parotid;  from  which  they  continue  to  the  neck. 

They  are  on  every  part  of  the  face,  and  unite,  so  that 
their  principal  trunks,  which  are  very  numerous,  pass 
over  the  basis  of  the  lower  jaw,  near  the  facial  artery. 
They  enter  into  glands,  which  are  also  very  numerous, 
immediately  under  the  jaw,  or  which  are  sometimes 
to  be  found  on  the  cheek,  at  the  anterior  edge  of  the 
masseter  muscle.  All  the  absorbents  of  the  exterior  part 
of  the  head  pass  to  the  glands  on  the  side  of  the  neck, 
already  described. 

Those  from  the  interior  of  the  nose  accompany  the 
ramifications  of  the  internal  maxillary  artery,  and  pro- 
ceed to  glands  behind  the  angle  of  the  lower  jaw;  into 
which  glands  also  enter  the  absorbents  of  the  tongue  and 
inner  parts  of  the  mouth. 

The  absorbents  of  the  thyroid  gland,  on  the  left  side, 
pass  down  to  the  thoracic  duct;  those  on  the  right,  unite 


383 


Absorbents  of  the  Hand  and  Arm. 

to  the  trunk  of  the  absorbents  on  that  side,  near  its  ter- 
mination. It  has  been  remarked  that  they  can  be  readily 
injected,  by  thrusting  the  pipe  into  the  substance  of  the 
gland. 


SECTION  II. 

Of  the  Absorbents  of  the  Arm  and  Upper  Part  of  the 

Trunk. 

The  absorbents  of  the  arm  are  superficial  and  deep- 
seated,  like  those  of  the  lower  extremity. 

The  superficial  absorbents  have  been  injected  on  the 
anterior  and  posterior  surfaces  of  the  fingers  and  the 
thumb,  near  their  sides.  On  the  back  of  the  hand  they 
are  very  numerous,  and  increase  considerably  in  their 
progress  up  the  fore  arm.  As  they  proceed  upwards,  they 
incline  towards  the  anterior  surface  of  the  fore  arm;  so 
that  by  the  time  they  have  arrived  at  the  elbow,  almost  all 
of  them  are  on  the  anterior  surface.  The  absorbents  on 
the  anterior  part  of  the  hand  are  not  so  numerous  as  those 
on  the  back.  Sometimes  there  are  digital  branches  from 
the  fingers,  and  an  arcus  in  the  palm;  but  this  bow  is  not 
formed  by  one  large  absorbent,  analogous  to  the  ulnar 
artery.  On  the  contrary,  its  two  extremities  are  continued 
over  the  wrist,  and  pass  on  the  fore  arm  like  the  absor- 
bents. 

At  the  elbow,  some  of  them  often  pass  into  one  or  two 
small  glands,  which  are  very  superficial;  but  the  whole  of 
the  absorbents,  somewhat  reduced  in  number,  as  some  of 
them  unite  together,  pass  along  with  the  bloodvessels  into 
the  hollow  of  the  arm  pit;  where  they  enter  the  axillary 
glands.  There  are  generally  one  or  more  vessels' which 
pass  in  the  course  of  the  cephalic  vein,  between  the  pec- 


384  Absorbents  of  the  Upper  Part  of  the  Trunk. 

toral  and  the  deltoid  muscle,  and  enter  into  some  of  the 
glands  under  the  clavicle. 

There  are  almost  always  several  glands  in  and  near  the 
axilla.  Some  of  them  are  very  near  the  great  bloodvessels; 
sometimes  one  or  more  of  them  are  much  lower;  some- 
times they  are  to  be  found  under  the  pectoral  muscle. 
They  are  commonly  not  so  large  as  those  of  the  groin, 
and  are  surrounded  with  fat. 

The  deep-seated  absorbents  originate  also  at  the  fin- 
gers, and  soon  accompany  the  branches  of  the  arteries. 
Those  which  attend  the  radial  artery,  originate  on  the 
back  of  the  hand,  and  also  in  the  palm,  where  they  are 
associated  with  the  arcus  profundus.  They  go  up  with  the 
radial  artery  to  the  elbow,  and  sometimes  pass  through 
a small  gland  about  the  middle  of  the  fore  arm. 

Those  which  attend  the  ulnar  artery,  commence  under 
the  aponeurosis  palmaris,  and  go  with  the  artery  to  the 
elbow;  at  the  bend  of  the  elbow  they  are  generally  joined 
by  one  or  more,  which  accompany  the  interosseal  artery; 
there  they  unite,  so  as  to  form  several  trunks  which  pass 
up  to  the  axilla  with  the  humeral  artery.  They  sometimes 
pass  through  one  or  two  glands,  which  are  near  the 
elbow;  and  they  receive  in  their  course,  deep-seated 
branches  from  the  muscles  on  the  humerus. 

The  absorbents  from  the  anterior  and  external  part  of 
the  thorax,  and  the  upper  part  of  the  abdomen,  also  pro- 
ceed to  the  axilla,  and  enter  into  the  glands  there;  those 
which  are  deep-seated,  joining  the  deep-seated  vessels. 
The  absorbents  of  the  mammae  pass  to  the  same  glands; 
and  when  they  are  affected  with  the  virus  of  cancer,  can 
often  be  perceived,  in  their  course,  in  the  living  subject. 

The  absorbents  of  the  uppermost  half  of  the  back,  and 
those  of  the  back  of  the  neck,  go  likewise  to  the  axilla. 

The  absorbent  vessels,  collected  from  these  various 
sources,  proceed  from  the  exterior  to  the  innermost 
glands,  but  with  a considerable  diminution  of  their  num- 


Facts  relating  to  Cutaneous  Absorption.  385 

ber;  they  accompany  the  subclavian  vein,  and  are  reduc- 
ed to  one  or  two  trunks,  that  generally  unite  before  their 
termination.  On  the  left  side , the  absorbents  of  the  head 
and  neck  generally  open  into  the  thoracic  duct,  as  has 
been  already  observed;  and  those  of  the  left  arm  also 
open  into  the  thoracic  duct,  or  into  the  subclavian  vein 
very  near  it.  On  the  right  side  the  absorbents  from  each 
of  these  parts  empty  into  the  common  trunk,  which 
often  is  formed  by  the  union  of  large  vessels,  from  four 
sources;  viz.  the  Head,  the  Thyroid  gland,  the  right  Arm, 
and  the  right  cavity  of  the  Thorax,  &c.  The  diameter  of  the 
trunk  is  very  considerable;  but  it  is  often  not  more  than 
half  an  inch  in  length.  It  generally  opens  into  the  right 
subclavian  vein,  at  the  place  where  it  unites  to  the  right 
internal  jugular. 

Two  respectable  physiologists  of  Europe  (M.  Seguin,  of 
Paris,  and  the  late  Dr.  Currie,of  Liverpool)  have  doubted 
whether  absorption  takes  place  on  the  external  surface  of 
the  skin.* — This  question  has  been  examined  in  a very 
interesting  manner  by  several  graduates  of  the  university 
of  Pennsylvania,  who  chose  it  for  the  subject  of  their  in- 
augural theses;  viz.  Drs.  Rousseau,  Klapp,  Daingerfield, 
Mussey,  and  J.  Bradner  Stewart. 

The  three  first  of  these  gentlemen  state,  that  when  spirit  of 
turpentine,  and  several  other  substanc-es  which  are  com- 
monly supposed  to  be  absorbed  by  the  skin,  were  applied 
to  it  in  a way  which  prevented  their  volatile  parts  from 
entering  the  lungs  by  respiration,  no  absorption  took  place. 
But  when  they  inspired  air  impregnated  with  exhalations 

* I believe  that  M.  Seguin’s  Memoir  on  this  subject  was  read  to 
the  Academy  of  Sciences  a short  time  before  the  meetings  of  that 
body  were  suspended.  It  was  published  by  M.  Fourcroy,  in  La  Me- 
dicine Eclairee  par  les  Sciences  Physiques,  vol.  iii. — An  extract  from 
M.  Fourcroy’s  publication  may  be  seen  in  the  19th  chapter  of  the  first 
volume  of  Dr.  Currie’s  “ Medical  Reports  oii  the  Effects  of  Water,” 
&c.,  in  which  is  also  contained  a statement  of  the  Doctor’s  own  expe- 
riments and  reflections, 

Voi.  ir.  3 c 


386  Experiments  of  K.  Boerhaave  and  J.  Hunter. 

from  these  substances,  they  perceived  satisfactory  proofs 
that  the  exhalations  entered  the  system.  From  these  facts 
they  inferred  that  when  those  articles  entered  the  body 
by  absorption,  they  were  taken  in  by  the  lungs,  and  not 
by  the  external  surface. 

On  the  other  hand,  the  two  gentlemen  last  mentioned,  state 
that  after  immersing  themselves  in  a bath  consisting  of 
a decoction  of  rhubarb,  of  madder,  or  of  turmeric,  their 
urine  became  tinged  with  these  substances.  They  also 
assert  that  the  colouring  matter  of  these  different  articles 
is  not  volatile}  and,  therefore,  could  not  have  entered  the 
lungs  during  the  experiments.* 

The  statement  in  page  364,  from  Dr.  Soemmering,  that 
when  mercury  is  injected  backwards  in  the  absorbent 
vessels  which  originate  on  the  foot,  it  will  sometimes 
appear  in  small  globules  on  the  skin  of  the  foot,  has  an 
important  connexion  with  this  subject.f 


About  the  middle  of  the  last  century,  it  was  generally  be- 
lieved by  anatomists,  that  absorption  was  performed  by 
the  veins.  This  doctrine  seemed  to  be  established  by  the 
experiments  of  Kaaw  Boerhaave,  which  are  related,  with 
many  other  interesting  statements,  in  his  work  entitled 
“ Perspiratio  Dicta  Hippocrati,”  &c.,  published  at  Ley- 
den, in  1738.  In  these  experiments  it  appeared  to  the 
author,  that  when  the  stomach  of  a dog  was  emptied  of 
its  contents,  and  filled  with  warm  water,  immediately 
after  death,  the  water  passed  into  the  minute  ramifica- 

* The  Thesis  of  Dr.  Rousseau  was  published  in  1800.  Those  of 
Drs.  Klapp  and  Daingerfield  in  1805.  Dr.  Mussey  published  in  the 
Third  Supplement  to  the  Medical  and  Physical  Journal  of  Dr.  Barton, 
in  1809.  Dr.  Stewart  published  in  1810. — Additional  observations  by 
Drs.  Klapp,  Rousseau  and  Smith,  are  published  in  the  Philadelphia 
Medical  Museum,  Vol.  I.  new  series. 

f Since  the  publication  of  the  first  volume,  the  author  has  enjoyed 
the  advantage  of  consulting  a translation,  in  manuscript,  of  some  parts 
of  the  German  edition  of  Dr.  Soemmering’s  valuable  work  on  the 
Structure  of  the  Human  Body. 


387 


Experiments  of  Magendie  and  Delile. 

lions  of  the  veins  of  the  stomach,  and  from  them  to  the 
vena  portarum,  and  ultimately  to  the  heart,  in  large 
quantities. 

This  account  appears  to  be  disproved  by  some  experiments 
of  the  late  John  Hunter,  made  about  twenty  years  after, 
and  published  in  the  Medical  Commentaries  of  Dr. 

William  Hunter,  Part  I. Mr.  Hunter’s  experiments 

have  been  considered  as  establishing  the  fact,  that  absorp- 
tion (in  the  intestines  at  least)  is  performed  exclusively 
by  the  lacteals,  or  proper  absorbent  vessels,  and  not  at  all 
by  the  veins.  Kaaw  Boerhaave  is  of  course  supposed  to 
have  been  mistaken;  and  Mascagni,  who  has  repeated 
his  experiment,  refers  the  appearance  of  water  in  the 
veins  to  transudation,  through  the  coats  of  the  intestines; 
which  he  has  observed  to  take  place  to  a great  degree. 

In  the  year  1809,  a memoir  was  presented  to  the  national 
institute  of  France  by  Messrs.  Magendie  and  Delile, 
which  contains  an  account  of  some  experiments  that  have 
an  important  relation  to  the  above  mentioned  subject.* 
— The  authors  being  greatly  surprised  at  the  rapidity 
with  which  the  poisoaof  Java,  &c.  appeared  to  enter  the 
sanguiferous  system,  instituted  a series  of  experiments 
to  determine  whether  these  substances  proceeded  to 
that  system  by  the  circuitous  route  of  the  absorbent 
vessels,  or  by  the  shorter  course  of  the  veins.  Two  of 
their  experiments  are  especially  interesting.  They  made 
an  incision  through  the  parietes  of  the  abdomen  of  a 
living  dog,  who  had  eaten  a large  quantity  of  meat  some 
hours  before  (that  his  lacteals  might  be  visible  from  their 
distention  with  chyle),  and,  drawing  out  a portion  of  the 
small  intestine,  they  applied  two  ligatures  to  it,  at  the 
distance  of  five  inches  from  each  other.  The  portion  of 
intestine  between  these  ligatures  was  then  separated  by 
incision  from  the  rest  of  the  intestinal  tube,  and  all  the 
lacteals,  bloodvessels,  See.  which  passed  to  and  from  it, 
were  divided,  except  one  artery  and  a vein.  A consider- 

* The  title  of  the  paper  is  a (C  Memoir  on'  the  Organs  of  Absorption 
in  Mammiferous  Animals.”  A translation  of  it  was  published  in  the 
Medical  and  Philosophical  Register  of  New  York,  and  in  several 
other  periodical  works. 


388  Experiments  of  Magendie  and  Delile. 

able  length  of  this  artery  and  vein  were  detached  from 
all  the  surrounding  parts,  so  that  the  authors  supposed 
these  vessels  to  form  the  only  connexion  between  the 
portion  of  the  intestine  and  the  rest  of  the  body.  Into 
the  cavity  of  the  intestine,  which  was  thus  circum- 
stanced, they  introduced  a small  quantity  of  the  poison, 
and,  to  their  astonishment,  it  produced  its  fatal  effects 
in  the  same  manner  it  would  have  done  if  it  had  been 
introduced  into  the  intestine  while  all  its  connexions 
with  the  body  were  entire.  This  experiment,  they  assert, 
was  repeated  several  times,  without  any  dilference  in 
the  result. 

After  several  other  experiments,  they  finally  separated  the 
thigh  from  the  body  of  a living  dog  in  such  a manner 
that  the  crural  artery  and  vein  were  left  undivided.  A 
quill  was  then  introduced  into  the  artery,  and  two  liga- 
tures were  applied  to  fix  it  round  the  quill.  The  artery 
was  then  divided  between  the  ligatures.  The  vein  was 
managed  in  the  same  manner.  There  was,  therefore,  no 
communication  between  the  limb  and  the  body,  except 
by  the  blood  which  passed  through  the  divided  vessels 
and  the  quills.  The  poison  was  tiien  introduced  under 
the  skin  of  the  foot,  and  soon  occasioned  the  death  of  the 
animal:  its  deleterious  effects  commencing  about  four 
minutes  after  its  application  to  the  foot.  This  experiment 
appears  to  prove  decidedly  that  the  blood  is  the  vehicle 
by  which  poison,  when  applied  to  the  extremities,  is 
carried  to  the  body;  although  it  may  not  determine  the 
question  whether  this  poison  was  taken  up  by  the  absor- 
bents or  by  the  veins. 

Some  other  experiments  made  by  the  authors  gave  results, 
which  are  very  difficult  indeed  to  explain.  They  wished 
to  know  if  the  blood  of  an  animal  thus  contaminated, 
would  produce  similar  effects  upon  another  animal;  and, 
with  a view  to  ascertain  this  point,  they  insinuated  a 
small  piece  of  wood,  covered  with  the  poison,  into  the 
thick  part  of  the  left  side  of  the  nose  of  a dog.  Three  mi- 
nutes after  the  introduction  of  the  poison,  they  translused 
blood  from  the  jugular  vein  of  the  same  side,  into  one  of 
the  veins  of  another  dog.  About  one  minute  after  the 


Report  of  the  Committee  of  the  Institute.  389 

commencement  of  the  transfusion,  the  effects  of  the  poison 
began  in  the  dog  to  which  it  was  applied,  and  continued 
until  his  death.  Transfusion  into  the  veins  of  the  other 
dog  went  on  during  the  whole  time,  and  he  received  a 
large  quantity  of  blood  from  the  dying  dog,  without  pro- 
ducing any  effect. — They  varied  this  experiment  in  the 
following  manner.  The  thigh  of  a dog  was  separated 
from  the  body;  the  artery  and  the  vein  were  arranged 
as  in  the  former  experiment;  and  poison  was  introduced 
into  the  foot.  Three  minutes  after  the  introduction  of  the 
poison,  the  blood  of  the  crural  vein  was  passed  into  the 
jugular  vein  of  another  animal,  and  transfusion  was  con- 
tinued five  minutes  without  producing  any  effect  upon  the 
animal  receiving  the  blood:  it  was  then  stopped,  and  the 
crural  vein  was  so  arranged  that  the  blood  flowed  from 
it  into  the  animal  to  which  it  belonged.  This  animal  very 
soon  exhibited  symptoms  of  the  operation  of  the  poison.'^ 
From  these  very  interesting  experiments  the  authors  infer 
that  “ foreign  matters  do  not  always  proceed  through  the 
Lymphatic  or  Absorbent  Vessels , when  they  enter  into  the 
Sanguiferous  system .” 

This  memoir  was  referred  by  the  Institute  to  four  of  its 
members,  who  are  particularly  distinguished  by  their  pro- 
found knowledge  of  anatomy  and  physiology.  These  gen- 
tlemen, after  stating  their  belief  that  the  functions  of  the 
lymphatic  or  absorbent  system  have  been  completely  as- 
certained by  the  experiments  and  observations  of  Hunter, 
Cruikshank,  Mascagni,  &c.,  say  further,  that,  in  their 
opinion,  the  above  mentioned  inference  ought  to  be  a 
little  modified,  and  that  facts  are  not  sufficiently  nume- 
rous, or  applicable  to  the  point  in  question,  to  justify  the 
inference  that  foreign  matters  do  not  always  proceed 
through  the  Lymphatic  or  Absorbent  Vessels , when  they 
enter  the  Sanguiferous  system.  But  they  also  add,  that, 
as  the  author  is  still  engaged  in  a series  of  experiments 

* An  account  of  these  experiments  was  published  by  M.  Magendie 
in  a pamphlet.  A statement  of  them  is  also  contained  in  the  report 
made  to  the  Institute  by  the  committee  to  whom  the  memoir  was 
referred,  which  is  published  in  the  Journal  de  Physique,  for  March 
1813.  In  that  statement  this  last  mentioned  experiment  is  omitted. 


* 390 


Of  the  Absorbent  System. 

on  the  subject,  they  will  suspend  their  judgment  res- 
pecting the  inferences  to  be  deduced  from  the  present 
statement. 


The  most  extensive  account  of  the  absorbent  system  is  con* 
tained  in  the  “ Historia  et  Ichnographia  Vasorum  Lym- 
phaticorum  Corporis  Humani”  of  Mascagni. — “The 
Anatomy  of  the  Absorbing  Vessels  of  the  Human  Body, 
by  W.  Cruikshank;” — and  “The  Description  of  the 
Lymphatic  System,  by  Wm.  Hewson,”  (the  second 
volume  of  his  Experimental  Inquiries)— are  also  very 
interesting  publications. 


SYSTEM  OF  ANATOMY. 


APPENDIX. 


APPENDIX, 


OF  THE  BLOOD. 

f "T  ^ . • 

I HE  blood  of  a healthy  person  indicates  a tendency  to 
coagulate  very  soon  after  it  is  discharged  from  the  vessels 
which  naturally  contain  it,  although  it  is  perfectly  fluid 
in  those  vessels. 

If  it  remains  at  rest,  after  it  is  drawn  from  the  vessels, 
it  soon  coagulates  into  a solid  mass,  of  a soft  texture. 
From  this  solid  mass  a fluid  is  soon  observed  to  issue, 
which  first  appears  in  very  small  drops  on  almost  every 
part  of  the  surface.  These  drops  quickly  increase  and  run 
together,  and  in  a short  time  the  fluid  surrounds  the  solid 
mass,  and  exceeds  it  in  quantity. 

The  solid  part  which  thus  appears  upon  the  sponta- 
neous separation  of  the  blood,  is  denominated  Crassa - 
mentum  or  Cruor:  the  fluid  part  is  called  Serum. 

The  substance  which  contains  the  red  colour  of  the 
blood  remains  with  the  Crassamentum.  The  Serum,  when 
it  separates  without  agitation,  is  free  from  the  red  colour. 

The  colouring  matter  may  be  separated  completely 
from  the  Crassamentum  by  washing  it  with  water. 

The  blood,  therefore,  consists  of  three  parts,  viz.  the 
Serum;  the  Substance  which  coagulates  spontaneously ; and 
the  Colouring  Matter. 

Vol.  II. 


3D 


394 


Appendix. — Of  the  Blood, 


THE  SERUM 

Has  a considerable  degree  of  consistence,  although  it  is 
much  thinner  than  blood.  In  its  perfectly  natural  state,  it 
is  almost  transparent,  and  appears  to  be  very  lightly  ting- 
ed with  a greenish  yellow  colour;  but  it  is  very  often  im- 
pregnated with  a portion  of  bile,  which  is  probably  carri- 
ed to  the  bloodvessels  by  the  absorbents.  It  contains  a large 
quantity  of  albumen,  or  matter  like  the  white  of  an  egg. 
If  heated  to  140°  of  Fahrenheit,  it  becomes  opake;  and 
when  the  heat  is  increased  to  156  or  160,  it  is  firmly  co- 
agulated. It  is  also  coagulated  by  alcohol,  by  mineral 
acids,  and  by  rennet.'*  It  is  proved  by  chemists,  that  it 
contains  a small  quantity  of  pure  soda.  It  therefore 
changes  several  of  the  blue  colours  of  vegetables  green. 
It  is  also  found  to  contain  a similar  quantity  of  the  mu- 
riate and  the  phosphate  of  soda,  and  the  phosphate  of  lime. 
These  saline  substances  were  discovered  by  diluting 
serum  with  water,  and  exposing  the  mixture  to  heat,  by 
which  the  albumen  was  coagulated  into  flocculte:  these 
flocculre  were  separated  by  filtration:  the.  liquor  was  then 
diminished  by  evaporation,  and  the  salts  obtained  from  it 
by  crystallization. 

Serum  likewise  contains  a portion  of  sulphur  combined 
with  ammonia. 

When  it  is  exposed  to  a coagulating  heat,  a small  por- 
tion of  it  remains  fluid. 

This  fluid  portion  has  been  supposed  to  contain  a con- 
siderable quantity  of  gelatine;  but  it  is  contended  by  Mr. 
Brande,f  that  Gelatine  does  not  exist  in  the  serum  of  the 

* See  Mewson,  Vol.  I.  p.  139. — I suspect  that  some  particular 
management  is  necessary  in  the  use  of  rennet. 

f In  his  Researches  on  the  Blood,  communicated  to  the  Royal  So- 
ciety of  London  in  1812,  and  republished  in  the  Eclectic  Repertory, 
for  April  1813. 


Appendix. — Of  the  Blood.  395 

blood,  and  that  this  portion  consists  of  albumen  combined 
with  a proportion  of  alkali. 

It  is  also  asserted  by  Dr.  Bostock,*  one  of  the  latest 
writers  on  the  subject,  that  the  serosity  of  the  blood  (the 
term  applied  to  the  last  mentioned  fluid)  contains  no  ge- 
latine; but  that,  with  a minute  quantity  of  albumen,  it 
consists  of  a large  portion  of  an  animal  matter,  which  is 
different  either  from  gelatine  or  albumen,  being  unlikq 
either  of  them  in  its  chemical  qualities. 


THE  CRASS  AMENTUM 

Is  rendered  very  different  in  its  appearance,  by  the  dif- 
ferent circumstances  in  which  it  may  coagulate. 

When  the  blood  remains  at  rest  immediately  after  it  is 
drawn,  the  crassamentum  which  forms  in  it  is  a concrete 
substance,  without  the  smallest  appearance  of  fibre  in  its 
composition.  If  the  blood  is  stirred  with  a rough  stick, 
while  it  is  flowing  from  an  animal,  a large  portion  of  it 
will  concrete  upon  the  stick  in  a fibrous  form,  so  as  to 
resemble  a mass  of  entangled  thread,  some  of  the  red 
colouring  matter  still  adhering  to  it. 

The  crassamentum,  in  either  of  these  forms,  may  be 
washed  perfectly  white;  the  red  colouring  matter  passing 
completely  away  with  the  water.  In  this  state  it  appears}* 
to  have  all  the  chemical  properties  of  the  fibrous  matter 
of  muscular  flesh.  It  also  resembles  the  gluten  of  vegeta- 
bles, being  soft  and  elastic.  The  name  fibrin  is  now 
generally  applied  to  it. 

If  fibrin  is  washed  and  dried,  its  weight  is  very  small 
indeed  when  compared  with  that  of  the  blood  from  which 

* See  his  Observations  on  the  Serum  of  the  Blood,  in  the  Medico- 
Chirurgical  Transactions,  Vol.  II,  republished  in  the-Edectic  Re- 
pertory, for  October  1812. 

t By  the  experiments  of  Mr.  Charles  Hatchett,  published  in  the 
London  Philosophical  Transactions  for  1800. 


396 


Appendix. — Of  the  Blood. 

it  has  been  obtained.  It  is,  therefore,  probable  that  a con- 
siderable proportion  of  the  bulk  of  the  crassamentum,  as 
it  forms  spontaneously,  depends  upon  the  serum  which 
exists  in  it,  and  can  be  washed  away. 

The  spontaneous  coagulation  of  the  blood,  which  ap- 
pears to  depend  principally  upon  the  Fibrin,  may  be  pre- 
vented by  the  addition  of  several  foreign  substances  to  the 
blood,  when  it  is  drawn.  It  is  subject  to  great  variations 
that  depend  upon  the  state  of  the  body  at  the  time  of 
bleeding;  and  in  some  conditions,  it  does  not  take  place 
at  all.* 

In  a majority  of  dead  subjects  the  blood  is  found  more 
or  less  coagulated  in  the  veins;  but  in  some  subjects  it  is 
found  without  coagulation.  It  is  asserted  that  it  does  not 
coagulate  in  subjects  who  have  died  suddenly,  in  conse- 
quence of  anger,  lightning,  or  a blow  on  the  stomach. 

THE  COLOURING  MATTER. 

When  the  bloodvessels  in  the  transparent  parts  of 
certain  living  animals  are  examined  with  magnifying 
glasses,  it  appears  that  the  red  colour  of  the  blood  is  owing 
to  bodies  of  a globular  form,  which  are  diffused  through 
a transparent  fluid.  The  appearance  of  these  bodies  has 
been  examined,  with  great  attention,  by  many  physiolo- 
gists, since  the  publication  of  Leuwenhoeck,  in  the 
London  Philosophical  Transactions. f 

* See  an  Inquiry  into  the  Properties  of  the  Blood,  by  the  late  Win. 
Hevvson:  and  Experiments  by  his  son,  T.  T.Hewson,  in  the  Eclectic 
Repertory,  Jan.  1 8 ' 1. — See  also  a Treatise  on  the  Blood,  &c.  by  the 
late  J.  Blunter. 

t Among  the  most  distinguished  of  these  observers  were  Father 
de  la  Torre,  Haller,  Hevvson,  Fontana,  Spalanzani,  J.  Hunter,  Cavallo. 

Some  short  accounts  of  Leuwenhoeck’s  original  observations  on 
the  blood  are  to  be  found  in  the  Philosophical  Transactions  of  Lon- 
don, for  1664,  in  the  fasciculi  which  are  numbered  102  and  106.  A 
more  full  description  is  contained  in  Boerhaave’s  Academical  Lee 


397 


Appendix. — Of  the  Blood. 

Several  of  these  gentlemen  have  described  the  appear- 
ance of  the  blood  very  differently;  but  Haller,  Spalanzani 
and  J.  Hunter  agree  that  the  figure  of  the  red  particles  is 
globular.*  Hunter  observes  further,  that  the  red  globules 
do  not  run  into  each  other  as  two  globules  of  oil  would  do 
when  divided  by  water;  and  he  believes  that  they  cannot 
unite.  At  the  same  time  they  seem  not  to  have  the  pro- 
perties of  a solid:  for  when  circulating  in  the  vessels,  they 
assume  elliptical  forms,  adapting  themselves  to  the  size  of 
the  vessels.  They  also  excite  no  sensation  of  solidity 
when  touched. 

They  appear  to  be  more  heavy  than  the  other  parts  of 
the  crassamentum:  for  in  healthy  blood  the  lower  part  of 
the  mass  contains  more  of  the  colouring  matter  than  the 
upper  part;  and  in  the  blood  of  persons  who  labour  under 
acute  local  inflammation,  they  often  subside  completely 
from  the  upper  part;  and  thus  occasion  what  is  called,  by 
Mr.  Hewson,  the  inflammatory  crust , or  size. 

It  has  been  observed  by  Mr.  Hewson,  and  also  by  Mr. 
Hunter,  that  the  globules  do  not  retain  their  form  in  every 
fluid.  They  are  said  to  be  dissolved  very  quickly  in  water, 
and  then  they  form  a fine  clear  red.  Several  of  the  neutral 

• 

tures  on  the  Theory  of  Physic.  See  the  section  on  the  nature  of  the 
blood. 

The  glasses  of  Father  de  la  Torre  were  transmitted  from  Naples  to 
the  Royal  Society  of  London  in  1765.  They  were  accompanied  by  a 
letter  from  Sir  F.  H.  E.  Stiles,  to  which  are  subjoined  some  observa- 
tions by  the  Rev.  Father  himself.  The  letter  and  the  observations  are 
published  in  the  55th  volume  of  the  transactions  of  that  society. 

In  the  year  1798,  Tiberius  Cavallo  published  an  Essay  on  the 
Medicinal  Properties  of  Factitious  Air,  with  an  appendix  on  the 
Nature  of  the  Blood;  in  which  is  contained  a further  account  of  the 
glasses  of  De  la  Torre. 

* I believe  that  this  is  also  the  opinion  of  Fontana. — In  J.  Hunter’s 
work  on  the  Blood  there  are  some  interesting  observations  on  micro- 
scopical deceptions.  See  the  note,  commencing  in  page  39,  Bradford’s 
edition. 


398 


Appendix. — Of  the  Blood. 

salts,  when  dissolved  in  water,  prevent  the  solution  of  the 
globules.  Mr  Hunter  informs  us,  that  the  vitriolic  acid, 
when  greatly  diluted,  does  not  dissolve  them,  See.  The 
muriatic  acid,  when  three  times  as  strong  as  vinegar, 
destroys  their  colour  without  dissolving  them,  although 
when  more  diluted,  it  dissolves  them. 

The  colour  of  the  blood  has,  for  a long  time,  been  sup- 
posed to  depend  upon  Iron.  About  the  middle  of  the  last 
century,  Vincentius  Menghini  published  in  the  Transac- 
tions of  the  Academy  of  Sciences  of  Bologna,  an  account 
of  experiments  which  contributed  to  establish  this  senti- 
ment. In  this  account  he  stated,  that,  after  washing  the 
colouring  matter  from  the  crassamentum,  he  had  sepa- 
rated it  from  the  water  by  boiling;  in  which  case  it  either 
rose  to  the  surface  of  the  water,  or  subsided,  and  left  the 
water  clear.  After  drying,  with  a gentle  heat,  -some  of  the 
colouring  matter  thus  separated,  and  then  repeatedly 
washing  it,  he  found  that  it  contained  a considerable 
quantity  of  iron,  which  was  attracted  by  the  magnet. 

After  exposing  a large  quantity  of  the  colouring  matter 
to  an  intense  heat,  he  found  in  it  a small  piece  of  iron,  of 
a spherical  form,  but  hollow;  and  a powder  which  was 
attracted  by  the  magnet,  but  appeared  more  like  rust  of 
iron  than  iron  filings. 

He  believes  the  seat  of  this  iron  to  be  in  the  colouring 
matter  of  the  blood,  as  neither  the  serum  nor  fibrina 
appeared  to  contain  it. — According  to  his  calculation,  the 
blood  of  a healthy  man  contains  more  than  two  ounces  of 
iron. 

This  doctrine  of  Menghini  has  been  very  generally 
admitted;  and  several  chemists  of  the  first  character,  viz. 
Bucquet,  Fourcroy,  Vauquelin,  &c.  have  made  experi- 
ments to  ascertain  the  substances  with  which  the  iron  in 
the  blood  is  combined. 

But  within  a few  years,  doubts  have  been  expressed 


399 


Appendix. — Of  the  Blood. 

on  this  subject  by  several  physiologists,  and  especially  by 
Dr.  Wells,  and  Mr.  Brande. 

The  first  of  these  gentlemen,  in  his  “ Observations  and 
Experiments  on  the  Colour  of  the  Blood f published  in  the 
London  Philosophical  Transactions  for  1797,  states  three 
reasons  for  rejecting  the  opinion  that  the  colour  of  the 
blood  is  derived  from  iron. 

1.  The  colour  of  blood  is  destroyed  by  a heat  less  than 
that  of  boiling  water:  whereas  no  colour  arising  from  a 
metal  is  destroyed  by  exposing  its  subject,  in  a close  ves- 
sel, to  such  a heat. 

2.  If  the  colour  from  a metal,  in  any  substance,  be 
destroyed  by  any  alkali,  it  may  be  restored  by  the  imme- 
diate addition  of  an  acid;  and  the  like  will  happen  by  the 
addition  of*a  proper  quantity  of  an  alkali,  if  the  colour 
has  been  destroyed  by  an  acid.  The  colour  of  blood,  on 
the  contrary,  when  once  destroyed,  can  never  be  brought 
back,  either  by  an  acid  or  an  alkali. 

3.  If  iron  be  the  cause  of  the  red  colour  of  blood,  it 
must  exist  there  in  a saline  state;  since  the  red  matter 
is  soluble  in  water.  The  substances,  therefore,  which  de- 
tect the  smallest  quantity  of  iron  in  such  a state,  ought 
likewise  to  demonstrate  its  presence  in  blood;  but  upon 
adding  Prussian  alkali,  and  an  infusion  of  galls,  to  a very 
saturated  solution  of  the  red  matter,  he  could  not  observe 
“in  the  former  case  the  slightest  blue  precipitate;  or  in 
the  latter  that  the  mixture  had  acquired  the  least  blue 
or  purple  tint.” 

Mr.  Brande,  in  a paper  entitled  “ Chemical  Researches 
on  the  Blood”  &c.  communicated  to  the  Royal  Society  of 
London  in  1812,  relates  many  experiments  which  were 
made  on  the  colouring  matter  of  that  fluid,  with  acids, 
alkalies,  astringents,  &c.  &c.  From  these  experiments 
he  also  infers,  that  the  colouring  matter  of  the  blood  is 
perfectly  independent  of  iron. 

In  support  of  this  inference,  he  adds,  that  the  Armenian 


400  Appendix.— Structure  of  Glands. 

dyers,  in  the  preparation  of  their  finest  and  most  durable 
red  colours,  use  blood  in  addition  to  madder,  in  order  to 
insure  the  permanency  of  these  colours.  As  the  compounds 
of  iron  convert  the  colour  of  madder  to  grey  and  black, 
the  production  of  a bright  colour,  by  the  addition  of 
blood  to  madder,  he  regards  as  a proof,  that  iron  is  not 
the  colouring  matter  of  blood. 

Many  estimates  have  been  made  of  the  quantity  of 
blood  in  the  human  body;  but  some  of  the  best  informed 
physiologists  have  regarded  them  as  fallacious. 


STRUCTURE  OF  CLANDS. 

Any  original  structure  that  discharges  from  the  blood- 
vessels a fluid  different  from  those  which  they  naturally 
contain,  may  be  considered  as  glandular.  The  function  or 
process  by  which  such  fluids  are  derived  from  the  blood- 
vessels is  called  secretion. 

A structure  of  this  kind  seems  to  exist  in  very  different 
situations;  for  it  is  distinctly  circumscribed  in  many  of 
those  bodies  commonly  denominated  glands,  which  are 
of  a very  precise  form;  and  it  is  also  diffused  on  some 
very  extensive  surfaces.  The  gastric  liquor,  a most  im- 
portant secretion,  is  probably  discharged  from  vessels 
which  open,  like  exhalents,  on  the  internal  surface  of  the 
stomach;  and  not  from  any  circumscribed  bodies,  which 
are  generally  denominated  glands. 

The  name  of  gland  is  theoretically  applied  to  several 
bodies  which  cannot  be  proved  to  secrete  any  fluid  what- 
ever; and  also  to  those  bodies  connected  with  the  absor- 
bent vessels,  which  are  called  the  Lymphatic  Glands;  but 
it  is  most  commonly  appropriated  to  those  organs  which 
discharge  a fluid  different  from  the  blood. 

The  structure  by  which  mucus  is  secreted  in  some 
places,  appears  to  be  very  simple.  Thus  in  the  Schnei- 
derian membrane  and  the  urethra,  there  are  small  ducts 


Appendix. — Structure  of  Glands.  401 

from  four  to  six  lines  in  length,  and  equal  in  diameter  to 
a bristle,  which  appear  to  be  formed  of  the  membrane  on 
which  they  open.  From  these  ducts  mucus  issues  to  cover 
the  surfaces  of  these  membranes.  In  many  instances  there 
is  no  substance  resembling  that  of  the  circumscribed 
glandular  bodies,  connected  with  these  ducts;  but  the 
secreted  fluid  seems  to  be  discharged  into  the  ducts  from 
the  small  vessels  on  their  surfaces. — The  ducts  of  this 
nature  in  the  urethra  are  denominated  Lacuna. 

In  some  other  parts  of  the  body,  the  cavities  into  which 
mucus  is  discharged  are  somewhat  different,  both  in  form 
and  size,  from  those  above  mentioned,  and  are  called 
Follicles.  These  cavities  are  surrounded  with  more  or 
less  of  a pulpy  vascular  substance,  which  has  been  con- 
sidered as  glandular,  and  essential  to  the  mucous  secre- 
tion. 

The  circumscribed  bodies,  which  are  commonly  called 
glands,  differ  in  their  internal  appearance  and  texture, 
from  the  other  parts  of  animals.  The  substance  of  which 
they  consist  differs  very  much  in  the  different  glands;  and 
thus  renders  the  liver,  kidneys,  salivary  glands,  mammas, 
&c.,  very  different  from  each  other.  Some  glands,  as  the 
salivary,  &c.,  are  composed  of  several  series  of  lobuli  that 
successively  diminish.  The  smallest  of  these  are  denomi- 
nated Acini.  Each  of  them  is  connected  by  a small  artery 
and  vein,  to  the  large  bloodvessels  of  the  gland;  and  also 
sends  a branch  to  join  the  excretory  duct.  These  Acini 
are  therefore  connected  to  each  other,  by  the  bloodvessels 
and  excretory  duct  of  the  gland,  and  also  by  the  cellular 
membrane,  which  covers  them  externally,  and  occasions 
them  to  adhere  to  each  other  where  they  are  in  contact. 
In  consequence  of  this  structure,  these  glands  have  a 
granulated  appearance. 

The  liver,  when  incised  with  a sharp  instrument,  ap- 
pears differently;  but  when  broken  into  pieces,  it  seems 
Vol.  II.  3 E 


402  Appendix. — Structure  of  Glands. 

to  consist  of  small  acini.  Some  other  glands,  as  the  Pros- 
tate, appear  to  be  uniform  in  their  texture,  and  have  none 
of  this  granulated  appearance. 

The  structure  of  glands  has  long  been  an  interest- 
ing object  of  anatomical  inquiry,  and  was  investigated 
with  great  assiduity  by  those  eminent  anatomists,  Mal- 
pighi and  Ruysch. 

Malpighi,  as  was  formerly  observed,  used  ink  and 
other  coloured  fluids  in  his  injections.  He  was  also  very 
skilful  in  the  use  of  microscopes,  and  took  great  pains  in 
macerating  and  preparing  the  subjects  of  his  inquiries. 
Ruysch,  on  the  other  hand,  used  a ceraceous  injection, 
and  was  most  eminently  successful  in  filling  very  small 
vessels  with  it.  Malpighi  believed  that  there  were  fol- 
licles or  cavities  in  glandular  bodies,  which  existed  be- 
tween the  extremities  of  the  arteries  and  the  commence- 
ment of  the  excretory  ducts  of  those  bodies,  and  that  in 
these  cavities  the  secreted  fluids  underwent  a change.— 
Ruysch  contended,  that  the  arteries  of  glands  were  con- 
tinued into  excretory  ducts  without  the  intervention  of  any 
cavity  or  follicle;  that  the  small  bodies,  which  had  been 
supposed  to  contain  follicles  or  criptas,  were  foimed  by 
convolutions  of  vessels,  and  that  the  change  of  the  fluid, 
or  the  process  of  secretion,  is  produced  by  the  minute 
ramifications  of  the  artery. 

A very  interesting  account  of  this  subject  is  contained 
in  two  celebrated  letters,  which  passed  between  JBoer- 
haave  and  Ruysch  in  the  year  1721,  and  are  published  at 
the  end  of  the  fourth  volume  of  the  works  of  Ruysch. 

The  opinion  of  Ruysch  has  been  most  generally  adopt- 
ed by  anatomists,  and  has  derived  support  and  confirma- 
tion from  several  anatomists  since  his  time. — The  late 
Mr.  Hewson  declared  his  conviction  that  the  small  glo- 
bular bodies  which  are  scattered  through  the  kidneys, 
and  were  supposed  to  be  follicles  or  criptae,  are  merely 
Convoluted  arteries.  He  also  asserted,  that  the  acini  which 


Appendix. — Structure  of  Glands.  403 

appeared  in  the  mammae  as  large  as  the  heads  of  pins, 
when  the  excretory  ducts  of  that  gland  were  injected 
with  vermilion  and  painters’  size,  proved  to  be  the  mi- 
nute ramifications  of  the  excretory  duct,  which  divided 
very  suddenly  into  branches  so  small,  that  they  could 
not  readily  be  seen  by  the  naked  eye.* 

Notwithstanding  these  reasons  for  supposing  that  the 
excretory  ducts  of  glands  were  derived  simply  from  the 
arteries  of  those  bodies,  it  is  said  that  the  late  Dr.  W. 
Hunter  used  to  declare  his  belief,  that  there  was  a part 
in  glands  which  was  not  injected,  in  his  preparations; 
and  to  say  further,  that  he  believed  his  preparations  were 
injected  as  minutely  as  those  of  Ruysch. 

All  of  these  opinions  have  been  strenuously  contro- 
verted by  the  Italian  anatomist,  Mascagni,  who  believes 
that  the  arteries  terminate  only  in  veins;  and  of  course 
that  they  neither  form  exhalent  vessels,  nor  communi- 
cate with  the  excretory  ducts  of  glands.  His  idea  of  the 
structure  of  glands  is  different  from  those  either  of  Mal- 
pighi or  of  Ruysch.  He  supposes  that  glands  contain  a 
great  number  of  minute  cells;  that  the  arteries,  veinSj 
and  absorbent  vessels  are  spread  upon  the  surfaces  of 
these  cells,  in  great  numbers,  and  very  irregularly.  From 
these  cells  very  small  canals  originate,  which  unite  to 
form  the  small  branches  of  the  excretory  ducts.  Accord- 
ing to  his  idea,  the  secreted  fluid  is  discharged  through 
pores  or  orifices  of  the  bloodvessels,  into  the  cells,  and 
proceeds  from  them,  through  the  canals,  into  the  branches 
of  the  excretory  ducts.  Absorbent  vessels,  in  great  num- 
bers, originate  from  these  cells. 

In  his  great  work  on  the  absorbent  system,  when 
treating  on  the  termination  of  arteries  and  the  com- 
mencement of  veins,  (Part  I.  Section  2.)  he  asserts,  that 
if  the  kidneys  are  successfully  injected  with  size,  co- 


* See  Experimental  Inquiries,  vol  ii.  p.  178. 


404  Appendix . — Structure  of  Glands. 

loured  with  vermilion,  and  then  laid  open  by  a section 
with  a razor,  it  will  be  found  that  the  size  without  the 
colour  has  passed  into  cells,  which  are  very  numerous; 
that  the  arteries  and  veins  are  ramified  most  minutely  on 
the  surfaces  of  these  cells,  and  that  the  tubuli  uriniferi, 
as  well  as  the  absorbent  vessels,  originate  from  them. 

He  supposed  that  a considerable  portion  of  the  fluid 
thus  passing  off  from  the  bloodvessels,  is  commonly 
taken  up  by  the  absorbent  vessels  of  the  kidneys:  for  in 
two  cases  in  which  he  found  the  absorbent  vessels  ob- 
structed, a diabetes  existed,  which  he  considered  as  the 
effect  of  the  inactivity  of  the  absorbents.  He  asserts,  that 
in  the  liver,  pancreas,  mammas,  and  also  in  the  sali- 
vary and  lachrymal  glands,  the  minute  arteries  and  veins 
are  also  distributed  upon  the  surfaces  of  cells;  and  that 
very  small  canals  arise  from  these  cells,  and  unite  to 
form  the  small  branches  of  the  excretory  ducts. 

This  great  anatomist  appears  to  have  been  much  oc- 
cupied with  microscopical  observations,  and  has  gone 
largely  into  the  discussion  of  this  subject.* 

It  must,  however,  be  acknowledged,  that  no  information 
which  has  as  yet  been  obtained  respecting  the  structure 
of  glands,  enables  us  to  explain  their  wonderful  effect 
upon  the  fluids  which  pass  through  them.  It  remains 
yet  to  be  ascertained  why  one  structure  forms  saliva  and 
another  bile;  or  why  so  much  apparatus  should  be  neces- 
sary for  the  secretion  of  milk,  when  adipose  matter  ap- 
pears to  be  produced  by  the  mere  membrane  in  which  it 
is  contained. 

* The  late  Dr.  W.  Hunter,  in  his  Medical  Commentaries,  (p.  40,) 
avowed  his  belief,  that  the  fluids,  which  appear  occasionally  in  the 
various  cavities  of  the  body,  transude  through  the  coats  of  the  blood- 
vessels. Mr  Hewson  (Experimental  Inquiries,  Vol.  II.  Chap.  7.) 
suggested  several  reasons  for  dissenting  from  this  opinion;  but  Mas- 
cagni has  endeavoured  to  support  it — See  a long  note  to  the  above 
mentioned  section  of  his  work,  page  74. 


Appendix. — Structure  of  Glands.  405 

Dr.  Berzelius,  professor  of  chemistry  at  Stockholm,  in  a 
late  work  on  animal  chemistry,  asserts,  that  if  all  the 
nerves  going  to  a secretory  organ  are  divided,  secretion 
will  cease,  notwithstanding  the  continued  circulation  of 
the  blood.  From  this,  he  thinks,  that  secretions  depend 
upon  the  influence  of  nerves,  although  he  cannot  explain 
their  effect. 

Mr.  Home,  after  relating  some  experiments  upon  blood 
and  serum,  made  with  the  Voltaic  Battery,  proposes  the 
following  questions,  among  others:  Whether  a weaker 
power  of  electricity  than  any  which  can  be  kept  up  by 
art,  may  be  capable  of  separating  from  the  blood  the  dif- 
ferent parts  of  which  it  is  composed;  and  forming  new 
combinations  of  the  parts  so  separated? — Whether  the 
structure  of  the  nerves  may  enable  them  to  possess  a low 
electrical  power,  which  can  be  employed  for  that  purpose? 
See. 

See  the  London  Philosophical  Transactions,  for 
1809,  Part  II.* 


* Mr.  Wollaston  has  also  published  a small  paper  on  this  subject, 
in  the  Philosophical  Magazine,  V©1.  33. 


GLOSSARY, 

EXHIBITING 


The  Derivation  of  certain  Anatomical  Terms, 


GLOSSARY* 

EXHIBITING  THE  DERIVATION  OF  CERTAIN  ANATOMICAL 
TERMS. 


A. 

Acetabulum.  The  cavity  which  receives  the  head  of  the 
thigh-bone;  from  ace  turn  vinegar:  so  called,  because  it  repre- 
sents the  acetabulum  or  saucer  of  the  ancients,  in  which  vine- 
gar was  held  for  the  use  of  the  table. 

Acini.  From  acinus  a grape. 

Acromion.  A process  of  the  scapula;  from  xx,pa<;  extremity,  and 
apog  the  shoulder. 

Anastomosis.  The  communication  of  vessels  with  one  another; 
from  xia  through,  and  $opx  mouth. 

Anatomy.  The  dissection  of  the  human  body;  from  avz,  and  tsuvo 
to  dissect. 

Anconeus.  A muscle;  so  called  from  xyy.ai  the  elbow. 

Aorta.  Aopm;  from  xvg  air,  and  to  keep. 

Aponeurosis.  A tendinous  expansion;  from  uvt>,  and  vsvpav  a nerve; 
from  an  erroneous  supposition  of  the  ancients,  that  it  was 
formed  by  an  expansion  of  nerve. 

Apophysis.  A process  of  a bone;  from  axoQva  to  proceed  from 
A synonyme  of  process. 

Arachnoides.  A net-like  membrane;  from  a spider,  and 

likeness. 

Artery.  From  air,  and  mma  to  keep;  because  the  ancients  sup- 
posed that  air  only  was  contained  in  them. 

Arthrodia.  A species  of  connexion  of  bones;  from  xpSpovto  articu- 
late. 

Arytanoides.  The  name  of  two  cartilages  of  the  larynx;  also  ap- 
plied to  some  muscles  of  the  larynx;  from  ctpo-rx net.  a funnel, 
and  £i?o5  a shape. 


Vol.  IT 


By  Dr.  Hooper 
3 F 


410 


Glossary. 

Astragalus.  A bone  of  the  tarsus;  so  called  from  its  resemblance 
to  a die  used  in  ancient  games,  from  areayssAos  a cockal  or  die. 

Atlas.  The  first  vertebra  of  the  neck;  so  called,  because  it  sustains 
the  head:  from  the  fable  of  Atlas  being  supposed  to  have  sup- 
ported the  world;  or  from  «tA xu  to  sustain,  because  it  sustains 
the  head. 

Azygos.  A term  applied  to  parts  without  a fellow,  from  « priv.  and 
£uyo 5 a yoke,  because  it  has  no  fellow. 

B. 

Bursa.  A bag;  from  fivfpet:  generally  applied  to  the  bursse  muscosae. 


C. 

Cancelli.  Lattice  work;  generally  applied  to  the  recticular  substance 
in  bones. 

Cardia.  The  superior  opening  of  the  stomach;  from  naftix  the 
heart. 

Carotid.  The  name  of  some  arteries  of  the  neck  and  head;  from 
napoo  to  cause  to  sleep;  for,  if  tied  with  a ligature,  the  animal 
was  said  to  be  affected  with  coma. 

Car/ms.  Kix.fi rot;  the  wrist. 

Clavicula.  The  clavicle  or  collar-bone,  a diminutive  of  clavis  a key; 
so  called  from  its  resemblance  to  an  ancient  key. 

Clinoid.  Four  processes  of  the  sella  turcica  of  the  ethmoid  bone 
are  so  called,  from  xA <vn  a bed,  and  ei^cs  likeness;  from  their 
supposed  resemblance  to  a couch. 

Clitoris.  A part  of  the  female  pudenda,  enclosed  by  the  labia  ma- 
jora;  from  xAs<«  to  enclose  or  hide. 

Colon.  The  first  of  the  large  intestines;  from  x&iAov,  quasi  koiXov, 
from  y.oi Xoi  hollow. 

Coracoid.  From  x«g<*|  a crow,  and  e:Sos  resemblance;  shaped  likethe 
beak  of  a crow. 

Coronary.  From  corona  a crown.  The  vessels  of  the  heart,  sto- 
mach, &c.  are  so  called  because  they  surround  the  parts  in  the 
manner  of  a crown. 

Cotyloid.  From  norv Atj  the  name  of  an  old  measure,  and  resem- 
blance; resembling  the  kotule. 

Cranium.  The  skull;  xpavio*,  quasi  xxpauov,  from  napa  the  head. 

Cremaster.  A muscle  so  called;  from  nptgxu  to  suspend,  because  it 
suspends  the  testicle. 

Cribriform.  From  cribrum  a sieve,  it  being  perforated  like  a sieve. 


Glossary.  411 

Cricoid.  Annular,  round  like  a ring;  from  x^ixo s a ring,  and  e;2o; 
likeness. 

Cuboides.  A bone  of  the  foot;  from  x»£os  a cube,  and  ti2o;  likeness; 
because  it  resembles  a cube. 

Cuneiform.  Some  bones  are  so  called;  from  cuneus  a wedge,  and 
forma  likeness;  being  shaped  like  a wedge. 

D. 

Deltoid.  A muscle  resembling  the  Greek  letter  A;  from  A,  and  u$os 
resemblance. 

Diaphragm.  The  muscle  which  separates  the  thorax  from  the  ab- 
domen; from  $ix<p£ctT\a>  to  divide. 

Diarthrosis.  A moveable  connexion  of  bones;  from  to  arti- 

culate. 

Digastric.  From  twice,  and  yxrti%  a belly;  having  two  bellies. 

Diplue.  The  spongy  substance  between  the  two  tables  of  the  skull; 
from  dmXoti)  to  double. 

Duodenum.  The  first  portion  of  the  small  intestines;  so  called  be- 
cause the  ancients  supposed  that  it  did  not  exceed  the  breadth  of 
twelve  fingers;  from  duodcnus , consisting  of  twelve. 

Dura  Mater.  The  outermost  membrane  of  the  brain;  called  dura , 
because  it  is  much  harder  than  the  other  membranes,  and  mater , 
from  the  idea  of  the  ancients  that  it  was  the  source  of  all  the 
other  membranes. 

E. 

Embryo.  The  child  in  the  womb  is  so  called  before  the  fifth  month, 
after  which  it  is  termed  fatus;  from  epfi^voi  to  bud  forth. 

Enarthrosis.  An  articulation  of  bones;  from  m in,  and  agflgev  a joint 
or  articulation. 

Enteric.  Belonging  to  the  intestines;  from  an  entrail  or  in- 

testine. 

Epidermis.  The  scarf  or  outermost  skin;  from  em  upon,  and 
the  skin. 

Epididymis.  The  small  oblong  body  which  lies  above  the  testicles; 
from  e sn  upon,  and  SiHvp os  a testicle. 

Epigastric.  The  superior  part  of  the  abdomen;  from  est;  upon,  and 
the  stomach. 

Epiglottis.  A cartilage  of  the  larynx  so  called;  from  estv  upon,  and 
yXa-ths  the  aperture  of  the  larynx, being  situated  upon  the  glottis. 

Epiphysis.  A portion  of  bone  growing  upon  another  bone,  but  sepa- 
rated from  it  by  a cartilage:  from  t m upon,  and  tpvc*  to  grow. 


412  Glossai' y. 

Epiploon.  The  membranous  viscus  of  the  abdomen,  which  covers 
the  intestines,  and  hangs  to  the  bottom  of  the  stomach;  from  en-t- 
to  swim  upon. 

Ethmoid.  From  e6i to;  a sieve,  and  eiSoj  resemblance;  being  perforated 
like  a sieve. 

F. 

E'ascia.  An  expansion,  enclosing  other  parts,  like  a band;  from/<z«- 
cis  a bundle. 

Falciform.  Shaped  like  a scythe;  from  falx  a scythe. 

Fasciculus.  A little  bundle,  dim.  of Jascis  a bundle. 

Fauces.  The  plural  of/izw.r,the  top  of  the  throat. 

G. 

Ganglion.  rufyXio v,  a knot  in  the  course  of  a nerve. 

Gastrocnemius.  The  muscle  which  forms  the  thick  of  the  leg;  from 
a belly,  and  the  leg. 

Genlo.  Namescompounded  with  this  word  belong  to  muscles  which 
are  attached  to  the  chin,  as  genio-glossus — genio-hyoideus,  See.; 
from  yentov  the  chin. 

Ginglymus.  An  articulation;  from  yi[yXvfioi  a hinge. 

Glenoid  cavity.  From  yXrjti  a cavity,  and  u2of  resemblance. 

Glosso.  Names  compounded  with  this  word  belong  to  muscles 
which  are  attached  to  the  tongue;  as  glosso-pharyngeus — glosso- 
staphilinus,  8tc  ; from  yhao-ru  the  tongue. 

Glottis.  The  superior  opening  of  the  larynx  at  the  bottom  of  the 
tongue;  from  yXarlu  the  tongue. 

Gluteus.  The  name  of  a muscle;  from  yAaros  the  buttocks. 

Gomphdsis.  rofttpvnt,  a species  of  immovable  connexion  of  bones; 
from  yof/.Qoc  a nail,  because  one  bone  is  fixed  in  another  bone 
like  a nail  in  a board. 


H. 

Helix.  The  outward  circle  of  the  ear;  from  eiA&i  to  turn  about. 

Hepar.  The  liver,  an  abdominal  viscus. 

Hyaloid.  From  la a&j  glass,  and  likeness;  the  capsule  of  the  vi- 
treous humour  of  the  eye  is  so  called,  from  its  transparent  and 
glassy  appearance. 

Hymen.  The  membrane  situated  at  the  entrance  of  the  virgin  va- 
gina; from  fg.r,')  Hymen,  the  god  of  marriage. 

Hyoides.  A bone  of  the  tongue,  so  called  from  its  resemblance  to 
the  Greek  v;  from  v,  and  e id*;  resemblance. 


Glossary.  413 

Hyfiochondrium.  That  part  of  the  body  which  lies  under  the  carti- 
lages of  the  spurious  ribs;  from  We  under,  and  yovdg o?  a cartilage. 
Hyfiogastric.  The  lower  region  of  the  fore  part  of  the  abdomen; 
from  vxo  under,  and  yaviig  the  stomach. 

I. 

He  on.  A portion  of  the  small  intestines;  from  eiXta  to  turn;  being 
always  convoluted. 

Ischium.  The  part  of  the  os  innominatum  upon  which  we  sit;  from 
is -yva  to  sustain. 

L. 

Lacuna.  The  excretory  duct  of  the  glands  of  the  urethra  and  vagi- 
na; from  lacus  a channel. 

Lambdoidal  suture.  So  called  because  it  is  shaped  like  the  letter 
from  and  e/So;  resemblance. 

Larynx.  The  superior  part  of  the  windpipe;  xu%v yf  the  larynx. 

M. 

Masseter.  A muscle  of  the  face,  which  assists  in  the  action  of  chew- 
ing; pcMTrraopxi  10  chew. 

Mastoid.  From  pares  a breast,  and  ules  likeness;  shaped  like  a nip- 
ple or  breast. 

Mediastinum.  The  production  of  the  pleura,  which  divides  the  tho- 
rax intotwo  cavities;  from  medium  the  middle, quasi  in  medio  stare. 
Mesentery . The  membranes  to  which  the  intestines  are  attached; 
from  (tt'e-o?  the  middle,  and  tmgov  an  intestine,  because  it  is  in  the 
middle  of  the  intestines. 

Mesocolon.  That  part  of  the  mesentery  in  the  middle  of  the  colon; 

from  pares  the  middle,  and  xe Aov  the  colon. 

Metacarpus.  That  part  of  the  hand  between  the  carpus  and  fingers; 

from  peru.  after,  and  xot^o;  the  wrist. 

Metatarsus.  That  part  of  the  foot  between  the  tarsus  and  toes;  from 
(C4£t*  after,  and  retires  the  tarsus. 

Mylo.  Namescompounded  with  this  word  belong  to  muscles  which 
are  attached  near  the  grinders,  as  mylo-hyoideus , See.;  from  pvM 
a grinder  tooth. 

O. 

Odontoid.  Tooth-like;  from  c2xs  a tooth,  and  ude;  resemblance. 
QLsophagus.  The  canal  leading  from  the  pharynx  to  the  stomach; 
from  eiu>  to  carry,  and  epuya  to  eat;  because  it  carries  the  food 
into  the  stomach. 


414  Glossary . 

Olecranon.  The  elbow,  or  head  of  the  ulna;  from  o>Xn^  the  cubit,  and 
Kga.vov  the  head. 

Omentum.  An  abdominal  viscus;  so  called  from  omen  a guess;  be- 
cause the  soothsayers  prophesied  from  the  inspection  of  this  part. 

O?no.  Names  compounded  with  this  word  belong  to  muscles  which 
are  attached  to  the  scapula,  as  omo-hyoideus , See.,  from  upo 5 the 
shoulder. 

Omo/ilata.  The  scapula  or  shoulder  blade;  from  upo;  the  shoulder, 
and  nXcnvi  broad. 

Osteology.  The  doctrine  of  the  bones;  from  e? eov  a bone,  and  Xo'ytx; 
a discourse. 

P. 

Pancreas.  A viscus  of  the  abdomen;  so  called  from  its  fleshy  con- 
sistence; from  nctv  all,  and  xgs«s  flesh. 

Parenchyma.  The  substance  of  some  of  the  viscera  was  so  called, 
from  t a^yx.va  to  pour  through. 

Parotid  Gland;  from  near,  and  e«s  the  ear;  because  it  is  situ- 
ated near  the  ear. 

Pelvis.  A bony  cavity  shaped  like  a bason;  from  7riXvs  a bason. 

Pericardium.  The  membrane  which  surrounds  the  heart;  from  sreg; 
around,  and  the  heart. ' 

Pericranium.  The  membrane  which  covers  the  bones  of  the  skull; 
from  around,  and  x^.noi  the  cranium  or  head. 

Periosteum.  The  membrane  which  surrounds  the  bones;  from  a-£g< 
around,  and  <jg-gov  a bone. 

Peristaltic  motion  of  the  intestines;  from  irt^iXXa,  to  contract. 

Peritoneum.  The  membrane  lining  the  abdomen,  and  covering  its 
viscera;  from  to  extend  around. 

Phalanx.  The  bones  of  the  fingers  and  toes  are  called  phalanxes, 
from  their  regular  situation,  like  a (pxXxyZ, , or  arrangement  of 
soldiers. 

Pharynx.  A membranous  bag  at  the  end  of  the  mouth;  airo  m 
because  it  conveys  the  food  into  the  stomach. 

Phrenic  or  diaphragmatic  nerve.  <I>gsvs;  the  diaphragm;  from  tp^v  the 
mind;  because  the  ancients  supposed  it  to  be  the  seat  of  the  mind. 

Pia  Mater.  The  innermost  membrane  of  the  brain,  so  called  because 
it  embraces  the  brain  as  a careful  mother  folds  her  child. 

J'leura.  The  membrane  lining  the  thorax;  irXev^ct  the  side. 

Plexus.  A kind  of  net-work  of  vessels  or  nerves;  from  filecto  te 
weave  together. 


Glossary.  415 

Psoas.  A muscle  so  called;  from  •■pea  the  loin,  being  situated  in  the 
loins. 

Pterygoid  process.  From  «r7e§v | a pen  or  wing,  and  likeness;  so 
called  from  its  likeness  to  a pen  or  wing. 

Pylorus.  The  lower  orifice  of  the  stomach,  which  opens  into  the 
intestines;  from  ttvXbcj  to  guard  an  entrance,  because  it  guards  as 
it  were  the  entrance  of  the  bowels. 

R. ; 

Raphe.  A suture;  from  to  sew. 

Renes.  The  kidneys,  uno  ra  pov,  because  through  them  the  urine 
flows. 

Retina.  The  net-like  expansion  of  the  optic  nerve,  on  the  inner 
surface  of  the  eye;  from  rete  a net. 

Rhomboides.  A muscle  so  called  from  its  shape;  from  p's^Sos  a geo- 
metrical figure,  whose  sides  are  equal  but  not  right-angled,  and 
ados  a likeness. 

Rotiila.  The  knee-pan;  a dim.  of  rota  a wheel,  from  its  shape. 

S. 

Sacrum.  A bone  so  called;  from  sacer  sacred,  because  it  was  once 
offered  in  sacrifices. 

Salvatella.  A vein  of  the  foot,  so  called  because  it  was  thought  that 
opening  it  preserved  health,  and  cured  melancholy;  from  salvo 
to  preserve. 

Sanguis.  The  blood;  ro  rewtd  yvi», because  it  preserves  the  body. 

Sartortus.  A muscle  so  called,  because  tailors  cross  their  legs  with 
it;  from  sartor  a tailor. 

Scapha.  The  depression  of  the  outer  ear  before  the  anti-helix; 
from  o-xatpn  a little  boat  or  skiff. 

Scaphoides.  A bone  of  the  carpus,  so  called  from  its  resemblance  to 
a skiff;  from  a skiff,  and  likeness. 

Sclerotic.  A term  applied  to  the  outermost  or  hardest  membrane  of 
the  eye;  from  o-kX^bu  to  make  hard. 

Sesamoid  bones.  From  a grain,  and  u2o;  likeness;  from  their 

resemblance  to  the  semen  sesami. 

Sigmoid.  Parts  are  so  called  from  their  resemblance  to  the  letter  2; 
from  2,  the  letter  Sigma,  and  ttlot  likeness. 

Sphenoid.  From  e^v  a wedge,  and  tides  likeness;  shaped  like  a wedge. 

Sphincter.  The  name  of  several  muscles  whose  office  is  to  shut  up 
the  aperture  around  which  they  are  placed;  from  s-tpiyya  to  shut  up. 

Splanchnic,  From  o-jrAary^ve,  an  entrail, 


416  Glossary. 

Symfihysis.  A connexion  of  bones;  from  <rV/x.<pva  to  grow  together. 

Synarthrosis.  A connexion  of  bones;  from  aw  with,  and  apfyov  a joint. 

Synchondrosis.  A species  of  union  of  bones  by  means  of  cartilage; 
from  <rw  with,  and  ^avJpo?  a cartilage. 

Synneurosis.  A species  of  connexion  of  bones  by  ljneans  of  mem- 
brane; from  trw  with,  and  vev^ov  a nerve;  because  membranes, 
ligaments,  and  tendons,  were  by  the  ancients  considered  as 
nerves. 

Syssarcosis.  A species  of  connexion  of  bones  by  means  of  muscle; 
from  aw  with,  and  flesh. 

Systole.  The  contractile  motion  of  the  heart  and  arteries;  from  trw 
teAA*>  to  contract. 

T. 

Tendon.  From  ritvu  to  extend. 

Thorax.  The  breast  or.  chest. 

Thyroid.  From  a shield, and  likeness;  shaped  like  a shield. 

Trachea.  The  windpipe,  so  called  from  its  roughness;  from 
rough. 

Trochanter.  A process  of  the  thigh-bone,  so  called  from  t^o;  a 
wheel. 

U. 

Ulna.  A name  for  the  cubit;  from  aXevti  the  cubit. 

Ureter.  The  canal  which  conveys  the  urine  from  the  kidney  to  the 
bladder;  from  a%ov  urine. 

Urethra.  The  passage  through  which  the  urine  passes  from  the 
bladder;  from  xgov  the  urine. 

Uvea.  The  posterior  lamina  of  the  iris,  so  called  because  in  many 
animals  it  is  of  the  colour  of  unripe  grapes;  from  uva  an  unripe 
grape. 

Uvula.  The  conicle  substance  which  hangs  down  from  the  middle 
of  the  soft  palate:  so  called  from  its  resemblance  to  a grape.  A 
dim.  of  uva  a grape. 

V. 

Valves.  From  valve  folding  doors. 

Vertebra.  The  bones  of  the  spine  are  so  called;  from  verlo  to  turn. 

X. 

Xi/dioid.  So  called  from  the  resemblance  to  a sword;  from  a 
sword,  and  sidog  likeness. 

Z. 

Zygoma.  The  cavity  under  the  zygomatic  process  of  the  temporal 
bones;  from  £uyos  a yoke. 


INDEX. 


A. 

Abdomen 

Abernethy,  Mr.  statement  by  him  in  the  London  Phi- 
losophical Transactions 
case  of  termination  of  the  vena  porta- 
rum  in  the  vena  cava  below  the  liver 
description  by,  of  the  menseteric 
gland  of  the  whale 
Absorbent  vessels  - 

of  the  lower  extremities 
of  the  head  and  neck 
of  the  abdomen  and  thorax  - 
of  the  arm  and  upper  part  of  the  trunk 
Acetabulum  ..... 
Accessory  nerve  of  Willis  - 
Acini  of  the  liver  .... 

Adhesion  of  the  lungs  to  the  thorax  - - - 

Adipose  artery  - 

membrane  - 

Adjustment  of  the  center  of  gravity 
Alphabetical  arrangement  of  the  muscles 
Alveolar  artery  - - - - 

Anastomotic  artery  ..... 
Andre,  M.  St.  - - 

Animal  motion,  question  respecting  ... 
Aorta  ...... 

table  of  the,  exhibiting  the  distribution  of  its 
branches  - 

Appearance  of  the  caecum  and  colon 
Appendix  of  the  diaphragm 
Aqueducts  of  the  ear 
Aqueous  humour 

VOL.  II. 


Vol.l. 

Page 


98 


387 

395 

255 


398 

160 


202 

381 

357 


Vol.ll. 

Page 

81 

58 

135 

364 

361 

366 

382 
371 

383 

332 

129 

72 

271 


239 

283 


22.9 

288 

115 


3 G 


418 


INDEX. 


Arbor  vitae  - 
Arm,  bones  of  the  - 

nerves  of  the  - 

Arrangement  of  the  jejunum  and  ileon 
Arteries,  general  account  of  their  distribution 
Articulations,  general  account  of  - 
Astragalus  - 

articulation  of  the 
Auditory  nerve  - 
Auricular  artery  - 

Axillary  artery  - 

vein  .... 

Azygos,  vena  .... 


Vol.I. 

Page 

321 

109 


263 

142 

284 

380 


B. 

Baillie,  Dr.  ... 

Ball  of  the  eye  -----  33 7 

Barclay,  Dr.  ------ 

Basilar  artery  - 

Basilic  vein  ------ 

Basis  of  the  cranium  59 

brain  - - - - - 32 1 

Baynham,  Dr.  of  Virginia,  his  method  of  injecting  the 
rete  mucosum  -----  394 

Bell,  C.  - - - - - 359 

Bell,  John,  observation  of  - 

Berlin,  royal  academy  of  sciences  of  - - - 400 

Berzelius,  professor  of  chemistry  at  Stockholm,  his 
experiment  on  secretion  - 

Bichat,  M.  opinion  embraced  by,  respecting  the  ex- 
tent of  the  retina  - - - 351 

of  the  pores  of  the  cuticle  - - 401 

doubts  of,  the  existence  of  the  rete  muco- 
sum in  the  tongue  - - - 

his  solution  of  a problem 
doubts  of,  respecting  the  muscularity  of 
arteries  - 

on  the  structure  of  arteries 

Biliary  duct  ------ 

Biliary  and  pancreatic  ducts,  orifices  of  - 

Bile 

Bladder,  gall  - 


Vol.II. 

Page 


338 

111 

227 


236 

252 

299 

292 


76 

252 

249 

299 


136 


405 


21 

73 

220 

220 

135 

111 

137 

136 


INDEX. 


Vol.T. 

Page 


419 


Bladder,  urinary  - 

Blood  ...... 

colouring  matter  of  the  - 

Bloodvessels  in  general  - 

of  the  tongue  - - - - 

of  the  abdomen  - - - 

Boerhaave,  K.  experiments  of 
Bones,  structure  of 

formation  of  - 

terms  used  in  the  description  of  - 
Bostock,  Dr.  ------ 

his  assertion  respecting  the  blood 

Boyer,  M. 

Brachial  plexus  of  nerves  ... 

construction  of  the  - 

Brande,  Mr.  on  the  serum  of  the  blood  - 

his  chemical  researches  respecting  the 
blood  - 


Brain,  basis  of  - - - - - 321 

commissures  of  - - - - 317 

middle  artery  of 

nerves  of  - - - - 32 1 

British  anatomists  on  the  spleen  - - - 

Brodie  on  the  source  of  motion  in  the  heart  - 
Bronchi®,  black  glands  on 
Bronchial  artery  - 
Bucquet,  M.  - 
Buisson,  M.  - 

Bursae  mucosae  - - - - 265,  292 


Vol.H. 

Page 

157 

394 

396 

215 

23 

86 

386 


70 

394 

162 

337 

338 
394 

399 


246 

147 

80 

63 

262 

398 

331 


Caecum  ^ 

position  of 
Camper 

Canals,  semicircular 
Capsular  arteries 
veins 

Cardiac  plexus 
Carlysle,  Dr. 
Carotid  arteries 
Carpus 
Cauda  equina 


378 


155 

119 

328 


115 

126 

211 

271 

303 

355 

229 


420 


INDEX. 


Vol.I.  Vol.II. 


Page 

Page 

Cavallo,  Tiberius  ... 

. 

397 

Cavities  of  the  nose  ... 

. 

. 

53 

Cavity  of  the  cranium  ... 

- 

56 

tympanum 

- 

- 

366 

Cellular  membrane  ... 

. 

384 

Cerebellum  - 

- 

. 

320 

Cerebrum  .... 

. 

310 

Cephalic  vein  ... 

- 

- 

298 

Change  of  colour  in  negroes,  instance  of  - 

- 

395 

Changes  of  the  rete  mucosum  in  white  persons 

- 

396 

Change  of  position  in  the  stomach 

- 

96 

Choctaw  Indians,  custom  of  - 

- 

- 

62 

Chorda  Tympani  - - - - 

- 

373 

Choroid  coat  - - - 

- 

- 

341 

Ciliary  ligament  - 

- 

343 

processes  - 

- 

- 

348 

Circulation  in  the  placenta,  object  of  the 

- 

213 

Circumflex  artery  of  the  os  ilium 

- 

- 

280 

vein  - 

- 

305 

Clavicle  .... 

- 

- 

102 

Coat  of  th>e  liver  .... 

- 

129 

Cochlea  - - 

- 

- 

376 

Colon,  structure  of 

117 

valve  of  the  ... 

- 

- 

1 18 

Cooper,  Mr.  Astley  ... 

- 

83 

Cornea  .... 

- 

- 

339 

Coronary  veins  - 

- 

- 

290 

Corpora  albicantia  of  Willis 

- 

323 

Corpora  cavernosa  - 

- 

• 

1 80 

cells  of  the 

- 

181 

lutea  ... 

- 

- 

202 

Corpus  spongiosum  ... 

- 

182 

structure  of 

- 

- 

183 

Corpuscula  Arantii  ... 

- 

55 

Crassamentum  ... 

- 

- 

395 

Cremaster  muscle  - 

- 

169 

Cricoid  cartilage  ... 

- 

- 

31 

Cruikshank,  Mr.  Wm.  his  opinion  respecting  the  ves- 
sels between  the  rete  mucosnm  and 
cutis  ...  392,  394 

his  experiments  favourable  to  the  idea 
of  the  motions  of  the  heart  being  in- 
dependent of  the  brain  - 78 


INDEX. 


421 


Yol.  I.  Vol.n. 


Page  Page 

Cruikshank,  Mr.  Wrn.  his  ideas  relative  to  the  origin 

of  the  lacteals  ...  106,363 

his  description  of  the  appearance  of  the 

absorbents  of  the  kidney  * - 371 

his  injection  of  the  absorbents  of  the 

pancreas  ...  377 

his  demonstration  of  those  of  the  lungs  379 

Crural  nerve  .....  345 

Crystalline  lens  .....  355 

Cubital  nerves  .....  334 

Currie,  Dr.  (of  Liverpool)  ...  385 

Cuticle  ......  398 

Cuticle,  pores  of  - - - - * 399 

peculiar  permeability  of  - - - 401 

separation  of  the  - - - - 403 

chemical  qualities  of  the  ...  404 

Cuvier,  M.  his  opinion  respecting  the  vascular  con- 
volutions of  the  corpus  spongiosum  of 
the  horse  - - - - 191 


D. 

Daingerfield,  Dr.  his  experiments  - - 385 

Delile,  M.  his  memoir  on  the  organs  of  absorption  in 

mammiferous  animals  ...  38 7 

Desault,  M.  his  ideas  respecting  the  structure  of  the 

spleen  ....  145 

his  experiment  respecting  the  frontal  sinus  13 

Diaphragm  - 202 

nerves  of  the  - 336 

Digital  arteries  .....  260 

Dorsal  nerves  .....  342 

Dorsey,  Dr.  John  S.  - - - - - 71 

Duct,  thoracic  .....  37 7 

hepatic  - - - - - 132 

cystic  .....  135 

Ductus  venosus  - - ...  . 212 

Duodenum  .....  302 

Dupuytren,  M.  inference  from  his  statement  in  a 
volume  of  the  proceedings  of  the  Na- 
tional Institute,  respecting  the  nerves 
of  the  lungs  - 


Dura  mater 


305 


72 


422 


INDEX. 


E. 

Ear  - 

bones  of  the  - - - . 

Ellis  on  respiration  - 

Elbow,  articulation  of  the  - 

Emulgent  arteries  - 

veins  - - - - 

Epidermis  ..... 
Epididymis  - 

Epigastric  artery  .... 
vein  - 

Epiglottis  ..... 
Eustachian  tube  - 
External  pudic  arteries  - 

External  iliac  arteries  - 

iliac  veins  .... 
Eye,  description  of  the  orbit  of  the 
parts  auxiliary  to  the  - 
ball  of  the  - 

humours  of  the  ... 

dissection  of  the  » 

effect  of  the  solution  of  nitrate  of  silver  on 
hyaloid  coat  of  the  - 


Vol.I. 

Page 

361 

370 

274 


- 398 


368 


51 

331 

337 

352 

358 


the 


- 360 


Vol.  II. 
Page 


70 

271 

303 

166 

279 

306 

30 

281 

279 

305 


F. 


Face  ... 
Facial  artery 
Fauces,  isthmus  of  the 
Fallopian  tubes,  structure  of  the 
Falconer,  Mr.  on  the  spleen 
Falx  ... 

Femoral  artery 
vein 

Foetus,  head  of  - 

thorax  of  - 
trunk  of  - 
extremities  of 
Fibula  ... 


Fimbriae 

Fingers 

articulation  of  the 


32 

215 

29 

200 

147 

- 307 

280 

306 

63 

65 

101 

- 152 
136 

201 

129 

- 277 
141 


Foot 


INDEX. 

423 

Yol.I. 

Vol.  II. 

Page 

Page 

Fontana,  Abbe  .... 

- 

78 

on  the  structure  of  the  nerves 

150 

on  the  colour  of  the  blood 

- 

396 

Foramen  caecum  - - - - 

22 

lacerum  - 

- 60 

ovale  - 

50 

thyroideum  - 

- 98 

Forearm  - - - - - 

113 

interosseous  ligament  of  the 

- 286 

Fornix  - 

315 

Fossa  ovalis  - 

- 74 

Fourcroy,  M. 

- 

385 

French  anatomists,  their  peculiar  opinions  respect- 


ing the  course  of  the  blood  in  the  foetus  - - 73 

Fyfe,  Mr.  on  the  villi  ....  107 


G. 

Gall,  Dr.  ------  326 

Ganglions  - 312 

Gastric  liquor  - - - - - 100 

Gavard,  M.  proposition  of  ...  114 

Generation,  female  organs  of  - - - 192 

male  organs  of  ...  166 

Glands,  inguinal  .....  368 

Glands  on  the  bronchiae  ....  63 

of  the  mesentery  - - - - 115 

of  the  neck  ....  332 

Glandulae  Buccales  - 15 

Brunneri  ....  104 

Peyeri  - - - - - 104 

Molares  ....  246 

Renales  - - - - - -150 

Gluteal  artery  - - - - - 277 

Goodwin,  Dr.  his  explanation  of  the  effects  of  venous 

blood  on  the  heart  ...  73 

Graff  De,  his  successful  investigation  of  the  testicle  174 

Grew,  Dr.  - - - - - 400 


H. 

Haighton,  Mr.  a dissection  of  the  ear  recorded  by  - 383 

essay  of  - .....  36 

Haller,  M.  on  muscular  fibres  - - 155 

remarkable  sentiment  of  42 


424 


INDEX. 


Yoll. 

Page 

Haller,  M.  inclined  to  the  opinion  of  Ruysch  on  the 
spleen  .... 

a cavity  in  the  glandulae  renales  frequently 
found  by  - 

his  publication  in  the  Philosophical  Trans- 
actions of  London  - - - 

on  the  testicles  of  the  foetus  - 
his  great  attention  to  the  arterial  system 
his  observations  on  the  absorbent  vessels 
Hand  - - . . . -119 

Hatchet,  Mr.  Charles  - 
Heart,  description  of  the 

Hepatic  artery  ..... 
veins  - 

Hewson,  Mr.  William,  on  the  villi 

his  opinion  respecting  the  spleen 
on  serum  - 

on  the  crassamenlum  - 
on  the  colour  of  the  blood 
on  the  structure  of  glands 
Hewson,  Dr.  T.  T.  his  experiments  on  the  blood 
Home,  Mr.  Croonian  lecture  of  - - - 160 

his  assertion  respecting  the  membrana 
tympani  ....  368 

confirmation  of  the  account  of  the  vesicles 
in  the  spleen  ... 
his  questions  relative  to  the  blood 
Hottentots,  female,  peculiarity  of  the 
Humboldt,  M.  on  the  experiments  of  Legallois  ' - 
Humeral  artery  - 
Hungarians,  peculiarity  of  the 

Hunter,  Dr.  William  ....  387 

opinion  of,  on  the  villi  - 
his  opinion  respecting  the  structure  of 
glands  - 

belief  respecting  a part  in  glands  not  in- 
jected in  his  preparations 
his  ideas  of  fluids  which  appear  in  vari- 
ous cavities  of  the  body  - 
Hunter,  Mr.  John  - 

his  opinion  respecting  the  vascular  struc- 
ture of  the  corpus  spongiosum  urethrae 


Vol.ll. 

Page 

146 

151 

174 

211 

251 

362 

395 
50 

266 

301 

106 

147 
394 

396 

397 
402 
396 


148 

405 

208 

79 

255 

211 

71 

106 

403 

403 

404 
100,177 


191 


INDEX. 


425 


Vol.T. 

Vol.lL 

Page 

Page 

Hunter,  Mr.’ John,  fact  established  by  experiments  of 

387 

on  the  structure  of  arteries 

- 

- 

219 

on  the  colour  of  the  blood 

- 

397 

Hypogastric  artery  ... 

- 

- 

274 

vein  - 

- 

304 

I— J. 

Iliac  arteries  - 

- 

273 

veins  .... 

- 

- 

304 

Injected  preparations,  examination  of 

- 

261 

Instances  of  peculiar  arrangement  of  veins 

- 

- 

307 

Intercostal  arteries  ... 

- 

263 

veins  ... 

- 

- 

292 

Interosseal  artery  ... 

Internal  basis  of  the  cranium 

- 

56 

259 

Intestines  .... 

- 

103 

division  of  - 

. 

- 

108 

Iris  ..... 

Ischiatic  artery  ... 

- 

344 

277 

Jejunum  and  ileon  ... 

- 

111 

Jones,  Dr.  .... 

- 

- 

220 

Jugular  veins,  internal  - 

- 

395 

external 

- 

- 

397 

Jussieu,  M.  account  by,  of  a female  born 

without 

a 

tongue  .... 

- 

27 

K. 

Kidneys  - 

- 

- 

152 

cortical  and  tubular  portions  of  the 

- 

155 

nerves,  lymphatics,  and  coat  of  the 

- 

- 

156 

absorbents  of  the 

- 

371 

Klapp,  Dr.  .... 
Knee,  articulation  of  the  ... 

~ 

- 

• 

280 

385 

L. 

Labia  externa 

Labyrinth  .... 

- 

. 

- 

374 

193 

contents  of  the 

. 

- 

379 

functions  of  the  different  parts  of 

- 

383 

Laennec,  M.  - - - - . 

Lachrymal  gland  - 

- 

- 

334 

129 

sac  ... 

*» 

• 

335 

Vol.IT.  3H 


426 


i 


INDEX. 


Vol.  I. 
Page 

LaCteals  - 
Larynx 

Legallois,  M.  experiments  of,  on  the  source  of  the 
motion  of  the  heart  - 
Lieberkuhn,  M.  - 

Lieutaud,  M.  ..... 

Ligaments  - - - - 28(5 

Liver  ...... 

absorbents  of  the  .... 

Lumbar  arteries  ..... 

veins  ..... 

nerves  ..... 

plexus  - * - 

Lungs,  ...... 

structure  of 
absorbents  of  - 

Lymphatics  in  the  spermatic  cord 

of  the  uterus  .... 


Vol.  IF. 
Page 
372 
31 

79 

106 

162 

125 

375 

273 

304 

343 

344 
64 
66 

379 

169 

204 


M. 

Magendie,  M.  experiments  of,  on  the  organs  of  ab- 
sorption in  mammiferous  animals 
Malformation,  cases  of 
Malpighi,  M.  on  the  structure  of  the  spleen 
on  the  structure  of  glands 
Mammary  artery  .... 

Marcet,  Dr. 

Mascagni,  M.  on  the  villi  ... 

on  the  absorbents  of  the  kidney 
assertion  of,  in  his  great  work  on  the 
absorbent  system 

his  ideas  respecting  the  structure  of 


glands  - 

Mastoid  cells  .....  369 

Maxilla  inferior  - - - - - 42 

Maxillary  arteries  - - - 

nerves  ..... 
Meatus  Auditorius  Externus  ...  364 

Interims  ...  379 

Meckle,  Professor,  his  opinion  respecting  the  outlets 

of  perspiration  - - 400 

on  the  nerves  of  the  face 


387 

71 

144 

402 

218 

71 

107 

371 


403 


403 


236 

319 


32-7 


INDEX. 


427 


Vol.  I. 
Page 


Mediastinum  - 

Median  nerve  - 

vein  - 

Meibomus,  glands  of  - 

Membrane,  adipose  - 

Schneiderian  - 

extent  of  - 

distribution  of 
Membrana  tympani  - 

observations  on  the 

Menghini,  Vincentius,  his  experiments  tending  to  es- 
tablishment the  opinion,  that  the  colour  of  the  blood 
depends  Upon  iron  - 

Mesentery  ------ 

construction  of 

root  of  - 

Mesenteric  artery  - 

vein  - 
Metacarpus  - 

Metatarsus  ------ 

Middle  hsemorrhoidal  vein  - 

sacral  vein  - - - - - 

Monro,  Dr.  on  the  Bursse  Mucosa 
on  the  iris  - 

Monro,  Dr.  opinion  of,  respecting  the  extent  of  the 
retina  - - - - - 

his  opinion  respecting  the  villi 
observation  of,  on  the  epididymis 
Morgagni,  M.  ventricle  of 
Motion,  muscular,  phenomena  of  - 
of  the  skeleton  - 

Mouth  ------ 

internal  surface  of  the  - - - 

Mucus  of  the  nose  - 

of  the  bladder  - 
Mussey,  Dr.  - 

Muscles,  alphabetical  arrangement  of  - 


N. 


334 

395 

5 

9 

10 

367 

373 


110 

111 

113 


124 

148 


265 

346 

351 


158 

159 


Nails  - 

Neck,  arteries  of  the 

absorbents  of  the 


255 


405 


Vol.  II. 
Page 
45 
339 
299 


398 


270 

302 


276 

304 


106 

174 

34 


14 

1 5 
12 

161 

385 


251 

382 


428 


INDEX. 


Vol.I.  Yol.il. 
Page  Page 

Neck,  muscles  of  the  - - - =210 


Nerves,  general  account  of  - 310 

Nichols,  Dr.  F.  - - - - - 147 

Nose  ......  1 

cavities  of  the  - - - 53  4 

nerves  of  6 

sinuses  of  - 12 


O. 

Obturator  artery  ... 
Occipital  artery  - 

Oesophagus  ... 
Olfactory  nerve  - 

Omentum,  origin  and  arrangement  of 


varieties  in  the  appearance  of 


Ophthalmic  artery 

- 

- 

- 

nerve 

- 

- 

- 

- 

Ovaries  - 

- 

- 

- 

Os  frontis 

- 

- 

- 

- 

14 

Ossa  parietalia 

- 

- 

- 

16 

Ossa  temporum 

. 

- 

- 

- 

18 

Os  occipitis 

- 

- 

- 

21 

Os  ethmoides 

- 

- 

- 

23,409 

Os  sphenoides 

- 

- 

- 

27 

Ossa  maxillaria  superiora 

- 

- 

- 

- 

32 

Ossa  nasi  - 

- 

- 

- 

36 

Ossa  unguis  = 

- 

- 

- 

• 

37 

Ossa  malarum 

- 

- 

- 

37 

Ossa  palati 

- 

- 

- 

- 

38 

Ossa  spongiosa 

- 

- 

- 

41 

Os  hyoides 

- 

- 

- 

- 

50 

Os  sacrum 

- 

- 

- 

79 

Os  coccygis 

- 

- 

- 

- 

81 

Os  ilium  - 

- 

- 

94 

Os  ischium  - J 

- 

- 

- 

- 

95 

Os  pubis 

' 

- 

- 

- 

97 

Os  humeri 

- 

- 

- 

- 

109 

Os  femoris 

- 

* 

- 

131 

Os  calcis 

- 

- 

- 

- 

143 

Os  naviculare 

- 

- 

- 

145 

Os  cuboides 

- 

- 

- 

- 

145 

Os  cuneiforme 

- 

- 

- 

146 

276 

235 

93 

315 

123 

124 
243 
318 
201 


INDEX. 


429 


Vol.I. 

Page 


139 


93 

289 


Palpebras  - 332 

Pancreas  ------ 

Pancreatic  duct  - - - - - 

Pancreas  enlarged,  symptoms  of  - 

Papillae  of  the  tongue  .... 

Par  Vagum  ------ 

Parotid  gland  - - - - - 

Patella  - - - - - ' - 

Pears,  Mr.  C.  account  by,  of  a woman  in  whom  the 
ovaria  were  deficient 
Peculiarity  of  the  liver 
Pelvis  - - . - 

ligaments  of  the 
absorbents  of  the 
Perforating  arteries  - 
Pericardium  - 

Peritoneum  - 
Periosteum  - 

Peroneal  artery  - 

nerve  - - - 

Pharyngeal  artery,  inferior  - 
Pharynx,  structure  of  the 
Phrenic  artery  - 

vein  - 

Physick,  Dr.  his  opinion  respecting  incisions  of  the 
cornea  ------ 

Pia  mater  ----- 

Pineal  gland  - 

Pleura,  arrangement  of  the  ... 

Plexuses  of  nerves  - - - - - 

Plexus  choroides  - - - - 

Pomum  Adami  - - - - - 

Popliteal  artery  - 

Pores  of  the  cutis  vera 
Portarum  vena 

Portio  Dura  ------ 

Posterior  iliac  artery  - 

Poupart’s  ligament,  method  of  preparing  it  for  exa- 
mination - ...  - - 192 

Priestley,  Dr.  - 

Primitive  iliac  arteries  - 


340 

306 

318 


!16 


- 391 


VoL  II 

Page 


139 

140 
140 

21 

328 

25 


208 

135 


371 

282 

49 

88 

286 

349 

234 

38 

265 

301 


45 

312 

32 

283 

13L 
325 
2 77 


70 

27S 


430 


INDEX. 


YoLI. 

Pag? 

Primitive  iliac  veins 
Proven§al,  Dr.  J.  M. 

Pudic  artery  ... 

Pulmonary  arteries  and  veins 
plexus 

Puncta  Lachrymalis 
Pylorus  - 

Q- 

Questions,  respecting  perspiration  ...  400 
the  structure  of  the  spleen 
Questions  of  Mr.  Home  - 


R. 

Radial  artery  - 

nerve  - 

Radius  - 

Reticular  membrane  ... 

Reaumur,  M.  - 

Rectum,  position  and  structure  of  - 
Renal  arteries  .... 
Reproduction  of  nerves  ... 

Rete  mucosum  - 

Retina  - 

Ribs  - - - - 

Ridley,  circular  sinus  of 
Rima  glottidis  - 

Rivinus,  professor,  erroneous  opinion  of 
Rolland,  M.  - - - - 

Rousseau,  Dr.  - 

Rush,  Dr.  James  - 

Ruysch,  M.  - 

preparation  of  - 

on  the  structure  of  the  spleen 

his  opinion  on  the  structure  of  glands 


116 

387 


393 

3-50 

83 

309 

368 


343 


S. 

Sabatier,  M.  idea  of,  respecting  the  bloodvessels  and 

the  colour  of  muscles  - - 156 

theory  of,  relative  to  the  foetal  circula- 
tion - 

observation  of,  on  the  stomach 


Vol.M. 

Page 

304 

72 

278 

60,308 

332 

101 


148 

405 


25  7 
34 1 


100 

120 

271 

314 


34 

27 

385 

124 

15 

144 

402 


74 

302 


INDEX. 


431 


Vol.I. 

Yol.II. 

Page 

Page 

Sabatier,  M.  supposition  of,  respecting  the  rectum 

119 

Sacral  artery  ... 

- 

- 

224 

Saliva  - 

- 

- 

26 

Salivary  glands  ... 

- 

- 

24 

Scapula  .... 

- 

- 

104 

articulation  of 

- 

- 

271 

Sciatic  nerve  - - - 

- 

- 

348 

plexus  ... 

- 

347 

Serum  - 

- 

- 

394 

Scheele,  Mr.  ... 

- 

- 

70 

Schneider,  Dr.  Conrad 

- 

- 

5 

Sheldon,  Mr.  John 

- 

- 

106 

Shippen,  Dr.  J.  G. 

- 

- 

114 

Sims,  Dr.  - 

- 

- 

374 

Skin,  vicarious  affections  of  the 

- 

- 

407 

Sone,  De  La,  opinion  of,  on  the  spleen 

- 

- 

146 

Soemmering,  interesting  discovery  of 

- 

- 

351 

idea  of,  respecting  the  papillae  of  the 

tongue 

- 

- 

•22 

opinion  of,  on  the  villi  - 

- 

- 

107 

statement  of,  respecting 

injections 

of 

absorbent  vessels 

- 

- 

364 

Smelling,  function  of  - 

- 

- 

11 

Spallanzani,  Abbe 

- 

- 

70 

dissertation  of 

- 

- 

100 

Spheno-Palatine  artery 

- 

- 

239 

Spleen,  general  account  of  - 

- 

- 

141 

absorbents  of  - 

- 

- 

376 

Spinal  marrow  ... 

- 

- 

327 

arteries  of  the 

- 

- 

329 

veins  of  the  - 

- 

- 

333 

Spermatic  arteries 

- 

- 

271 

veins  ... 

- 

- 

303 

Splenic  artery  ... 

- 

- 

267 

Stewart,  Dr.  J.  Bradner 

- 

- 

385 

Stiles,  Sir  F.  H.  E. 

-■ 

- 

397 

Stomach,  general  view  of  the 

- 

- 

95 

absorbents  of  - 

- 

- 

374 

Structure  of  ganglions 

- 

- 

307 

of  glands 

•-  ' 

- 

400 

Subclavian  arteries  - 

■ - 

- 

247 

veins 

- 

- 

302 

43-2 


INDEX. 


voi.i.  Voi.it. 
Page  Page 


Superior  mesenteric  Artery 

- 

- 

- 

- 

268 

vein 

- 

- 

- 

302 

Superior  vena  cava  - 

-• 

- 

. 

. 

391 

Sympathetic  nerve 

- 

- 

- 

351 

T. 

Tears 

. 

. 

. 

- 

335 

Teeth  - 

. 

- 

- 

45 

Temporal  artery 

- 

- 

. 

- 

240 

Thcbesius,  a German  Professor; 

, assertion  of 

- 

58 

Thigh 

■» 

- 

- 

■ 

130 

Thoracic  duct 

. 

. 

377 

Thorax 

. 

_ 

. 

. 

41 

Throat  - 

. 

. 

. 

29 

Thymus  gland 

- 

- 

- 

- 

67 

Thyroid  artery,  superior 

- 

- 

- 

232 

inferior 

- 

- 

- 

- 

248 

Tongue  - 

- 

- 

- 

18 

Torre,  Father  de  la  - 

- 

- 

- 

- 

397 

Trachea  - 

- 

- 

- 

62 

Tunica  Arachnoidea  - 

- 

- 

- 

- 

305 

Tunica  Conjunctiva 

- 

- 

333 

Tunica  Sclerotica 

- 

- 

- 

- 

338 

Tunica  Choroides 

- 

- 

- 

341 

Tunica  Hyaloidea 

- 

- 

- 

- 

353 

fluid  in  the 

- 

- 

- 

354 

Tympanum,  cavity  of  the 

- 

- 

- 

- 

366 

foramina  and  protuberances  of  the 

- 

369 

U. 

Umbilical  vessels 

- 

- 

- 

- 

211 

Ulna 

- 

- 

- 

114 

Ulnar  artery 

- 

- 

- 

- 

259 

nerve 

- 

- 

- 

340 

Urine 

- 

- 

- 

- 

164 

Uterine  artery 

- 

- 

- 

277 

Uterus 

- 

- 

- 

- 

197 

V. 

Valve  of  Eustachius 

- 

- 

- 

53 

Vieussens 

- 

- 

- 

- 

321 

Valvulae  Tricuspides 

- 

- 

- 

55 

INDEX. 


433 


Vol.  I. 

Vol.  II. 

Page 

Page 

Valyulae  Mitrales 

- 

- 

56 

Semilunares 

- 

55 

Vas  Deferens  ... 

- 

- 

175 

Vauquelin,  M. 

39S 

Vena  azygos  - 

- 

- 

292 

Vena  cava,  superior 

- 

291 

inferior 

■ - 

- 

300 

Vena  Galeni 

- 

319 

Vena  portarum  ... 

- 

- 

302 

Venae  vesicales  ... 

- 

304 

Ventricles  of  the  brain 

. 

■'  - 

313 

Veins,  particular  distribution  of 

- 

289 

Veins  of  the  heart 

- 

- 

290 

Vertebrae,  connexion  of,  with  the  head 

- s 

266 

articulation  of,  with  each  other 

- 

267 

Vertebrae,  true  ... 

- 

66 

Vertebrae,  false  - 

- 

- 

79 

Vertebral  artery  ... 

\ - 

249 

vein  - 

- 

- 

306 

Vesalius,  M.  his  method  of  examining 

the  brain 

317 

Vesication,  causes  of  - - 

- 

402 

Vestibule  ... 

- 

- 

376 

Vidius,  professor,  reputed  discoverer  of  the  pterygoid 

foramen  - 

- 

31 

Vieussens,  assertion  of  - 

- 

- 

58 

Vitreous  humour  ... 

- 

353 

W. 

Wells,  Dr.  ... 

- 

- 

399 

Wollaston,  Mr.  ... 

- 

405 

Winslow  ... 

- 

- 

73 

Wilson,  James,  Esq. 

- 

197 

Willis,  accessory  nerve  of 

- 

- 

332 

Wrist,  articulation  of 

- 

275 

3 I 


Vol.  II. 


ERRATA. 


VOLUME  I. 

Page  70.. ..8th  line  from  below,  for  cervical  read  vertebral. 

178.. . .1st  line,  for palati  read  palate. 

191. . ..7th  line,  for  their  facia  read  thin  facia. 

214..  ..10th  from  below,  l'o  r first  vertebra  of  the  neck  read  v ertebrce  of  the  neck. 

267.. .  lith  line,  for  bones  of  the  condyles  read  bases  of  the  condyles. 

323.. ..  10th  line,  for  Pons  Variolii  read  Pons  Varolii. 

345. . ..5th  line,  for  plain  read  plane. 

340,  354,  355,  356,  for  lamen  read  lamina — for  lamina  read  laminae. 

375  ...3d  line  from  below,  for  solid  read  hard. 

384  ...4th  line,  for  these  read  them. 

394.. .. 10th  line  from  below,  for  as  infection  read  as  an  injection. 

•407....  (title)  for  vicarious  connexion  read  vicarious  affections  of  the  skin. 

VOLUME  II. 

Page  94....  19th  line,  for  found  read  formed. 


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Accession  no. 

a a 09 9 

Aut^or  wistar^C. 
System  of  anatomy. 

1817  v . 2 


Call  no.  l8th  Cent, 
cop  .2 


